feat(core/bolt): allow back in multishare setup

### core/embed/rust/src/ui/layout_bolt/component/button.rs
@@ -396,6 +396,19 @@ impl Button {
         ))
     }
 
+    /// Create a button bar with an up-arrow back button on the left and a
+    /// confirm button on the right. The back button is only shown when
+    /// `show_back` is set, otherwise the confirm button takes the full width.
+    pub fn back_confirm(right: Button, show_back: bool) -> FixedHeightBar<BackConfirm> {
+        theme::button_bar(BackConfirm {
+            left: Button::with_icon(theme::ICON_UP)
+                .map(|msg| (matches!(msg, ButtonMsg::Clicked)).then(|| BackConfirmMsg::Back)),
+            right: right
+                .map(|msg| (matches!(msg, ButtonMsg::Clicked)).then(|| BackConfirmMsg::Confirmed)),
+            show_back,
+        })
+    }
+
     pub fn cancel_confirm_text(
         left: Option<TString<'static>>,
         right: Option<TString<'static>>,
@@ -486,6 +499,63 @@ pub enum CancelConfirmMsg {
     Confirmed,
 }
 
+#[cfg_attr(feature = "debug", derive(ufmt::derive::uDebug))]
+pub enum BackConfirmMsg {
+    Back,
+    Confirmed,
+}
+
+/// Button bar with an optional up-arrow back button on the left and a
+/// confirm button on the right. The confirm button takes the full width when
+/// the back button is not shown.
+pub struct BackConfirm {
+    left: MsgMap<Button, BackConfirmHandlerFn>,
+    right: MsgMap<Button, BackConfirmHandlerFn>,
+    show_back: bool,
+}
+
+type BackConfirmHandlerFn = fn(ButtonMsg) -> Option<BackConfirmMsg>;
+
+impl Component for BackConfirm {
+    type Msg = BackConfirmMsg;
+
+    fn place(&mut self, bounds: Rect) -> Rect {
+        let (left_area, right_area) = if self.show_back {
+            let (left, rest) = bounds.split_left(theme::BUTTON_WIDTH);
+            (left, rest.inset(Insets::left(theme::BUTTON_SPACING)))
+        } else {
+            (Rect::zero(), bounds)
+        };
+        self.left.place(left_area);
+        self.right.place(right_area);
+        bounds
+    }
+
+    fn event(&mut self, ctx: &mut EventCtx, event: Event) -> Option<Self::Msg> {
+        self.left
+            .event(ctx, event)
+            .or_else(|| self.right.event(ctx, event))
+    }
+
+    fn render<'s>(&'s self, target: &mut impl Renderer<'s>) {
+        if self.show_back {
+            self.left.render(target);
+        }
+        self.right.render(target);
+    }
+}
+
+#[cfg(feature = "ui_debug")]
+impl crate::trace::Trace for BackConfirm {
+    fn trace(&self, t: &mut dyn crate::trace::Tracer) {
+        t.component("BackConfirm");
+        if self.show_back {
+            t.child("left_button", &self.left);
+        }
+        t.child("right_button", &self.right);
+    }
+}
+
 type CancelInfoConfirm<F0, F1, F2> =
     FixedHeightBar<Split<MsgMap<Button, F0>, Split<MsgMap<Button, F1>, MsgMap<Button, F2>>>>;
 

### core/embed/rust/src/ui/layout_bolt/component/frame.rs
@@ -92,6 +92,28 @@ where
         self.with_button(theme::ICON_CORNER_INFO, CancelInfoConfirmMsg::Info)
     }
 
+    pub fn with_menu_button(self) -> Self {
+        self.with_menu_button_msg(CancelInfoConfirmMsg::Info)
+    }
+
+    fn with_menu_button_msg(mut self, msg: CancelInfoConfirmMsg) -> Self {
+        // The touch area is intentionally not expanded downwards so that the
+        // button does not overlap interactive content right below it (e.g.
+        // the number input's increment button).
+        let touch_area = Insets {
+            left: self.border.left * 4,
+            bottom: 0,
+            ..self.border
+        };
+        self.button = Some(Child::new(
+            Button::with_icon(theme::ICON_CORNER_MENU)
+                .with_expanded_touch_area(touch_area)
+                .styled(theme::button_moreinfo()),
+        ));
+        self.button_msg = msg;
+        self
+    }
+
     pub fn inner(&self) -> &T {
         self.content.inner()
     }

### core/embed/rust/src/ui/layout_bolt/component/mod.rs
@@ -40,8 +40,8 @@ mod welcome_screen;
 #[cfg(all(feature = "micropython", feature = "translations"))]
 pub use address_details::AddressDetails;
 pub use button::{
-    Button, ButtonContent, ButtonMsg, ButtonStyle, ButtonStyleSheet, CancelConfirmMsg,
-    CancelInfoConfirmMsg, IconText, SelectWordMsg,
+    BackConfirmMsg, Button, ButtonContent, ButtonMsg, ButtonStyle, ButtonStyleSheet,
+    CancelConfirmMsg, CancelInfoConfirmMsg, IconText, SelectWordMsg,
 };
 #[cfg(feature = "translations")]
 pub use coinjoin_progress::CoinJoinProgress;

### core/embed/rust/src/ui/layout_bolt/component/number_input.rs
@@ -12,7 +12,7 @@ use crate::ui::shape::{self, Renderer};
 #[cfg_attr(feature = "debug", derive(ufmt::derive::uDebug))]
 pub enum NumberInputDialogMsg {
     Selected,
-    InfoRequested,
+    Back,
 }
 
 pub struct NumberInputDialog<F>
@@ -24,7 +24,7 @@ where
     input: Child<NumberInput>,
     paragraphs: Child<Paragraphs<Paragraph<'static>>>,
     paragraphs_pad: Pad,
-    info_button: Child<Button>,
+    back_button: Child<Button>,
     confirm_button: Child<Button>,
 }
 
@@ -40,7 +40,7 @@ where
             input: NumberInput::new(min, max, init_value).into_child(),
             paragraphs: Paragraphs::new(Paragraph::new(&theme::TEXT_NORMAL, text)).into_child(),
             paragraphs_pad: Pad::with_background(theme::BG),
-            info_button: Button::with_icon(theme::ICON_CORNER_INFO).into_child(),
+            back_button: Button::with_icon(theme::ICON_UP).into_child(),
             confirm_button: Button::with_text(TR::buttons__continue.into())
                 .styled(theme::button_confirm())
                 .into_child(),
@@ -85,7 +85,7 @@ where
         self.input.place(input_area);
         self.paragraphs.place(content_area);
         self.paragraphs_pad.place(content_area);
-        self.info_button.place(grid.row_col(0, 0));
+        self.back_button.place(grid.row_col(0, 0));
         self.confirm_button.place(grid.cells(GridCellSpan {
             from: (0, 1),
             to: (0, 2),
@@ -98,8 +98,8 @@ where
             self.update_text(ctx, i);
         }
         self.paragraphs.event(ctx, event);
-        if let Some(ButtonMsg::Clicked) = self.info_button.event(ctx, event) {
-            return Some(Self::Msg::InfoRequested);
+        if let Some(ButtonMsg::Clicked) = self.back_button.event(ctx, event) {
+            return Some(Self::Msg::Back);
         }
         if let Some(ButtonMsg::Clicked) = self.confirm_button.event(ctx, event) {
             return Some(Self::Msg::Selected);
@@ -111,7 +111,7 @@ where
         self.input.render(target);
         self.paragraphs_pad.render(target);
         self.paragraphs.render(target);
-        self.info_button.render(target);
+        self.back_button.render(target);
         self.confirm_button.render(target);
     }
 }
@@ -125,7 +125,7 @@ where
         t.component("NumberInputDialog");
         t.child("input", &self.input);
         t.child("paragraphs", &self.paragraphs);
-        t.child("info_button", &self.info_button);
+        t.child("back_button", &self.back_button);
         t.child("confirm_button", &self.confirm_button);
     }
 }

### core/embed/rust/src/ui/layout_bolt/component_msg_obj.rs
@@ -1,12 +1,12 @@
 use core::convert::TryInto;
 
 use super::component::{
-    AddressDetails, ButtonPage, CancelConfirmMsg, CancelInfoConfirmMsg, CoinJoinProgress, Dialog,
-    DialogMsg, FidoConfirm, FidoMsg, Frame, FrameMsg, Homescreen, HomescreenMsg, IconDialog,
-    Lockscreen, MnemonicInput, MnemonicKeyboard, MnemonicKeyboardMsg, NumberInputDialog,
-    NumberInputDialogMsg, PassphraseKeyboard, PassphraseKeyboardMsg, PinKeyboard, PinKeyboardMsg,
-    Progress, SelectMenu, SelectMenuMsg, SelectWordCountMsg, SelectWordMsg, SetBrightnessDialog,
-    SimplePage,
+    AddressDetails, BackConfirmMsg, ButtonPage, CancelConfirmMsg, CancelInfoConfirmMsg,
+    CoinJoinProgress, Dialog, DialogMsg, FidoConfirm, FidoMsg, Frame, FrameMsg, Homescreen,
+    HomescreenMsg, IconDialog, Lockscreen, MnemonicInput, MnemonicKeyboard, MnemonicKeyboardMsg,
+    NumberInputDialog, NumberInputDialogMsg, PassphraseKeyboard, PassphraseKeyboardMsg,
+    PinKeyboard, PinKeyboardMsg, Progress, SelectMenu, SelectMenuMsg, SelectWordCountMsg,
+    SelectWordMsg, SetBrightnessDialog, SimplePage,
 };
 use crate::micropython::{Error, Obj};
 use crate::strutil::TString;
@@ -15,9 +15,9 @@ use crate::ui::component::placed::GridPlaced;
 use crate::ui::component::text::paragraphs::{ParagraphSource, Paragraphs};
 #[cfg(not(feature = "clippy"))]
 use crate::ui::component::Timeout;
-use crate::ui::component::{Component, FormattedText, Never, Paginate};
+use crate::ui::component::{Component, FlowMsg, FormattedText, MsgMap, Never, Paginate};
 use crate::ui::layout::obj::ComponentMsgObj;
-use crate::ui::layout::result::{CANCELLED, CONFIRMED, INFO};
+use crate::ui::layout::result::{BACK, CANCELLED, CONFIRMED, INFO};
 
 impl TryFrom<CancelConfirmMsg> for Obj {
     type Error = Error;
@@ -30,6 +30,17 @@ impl TryFrom<CancelConfirmMsg> for Obj {
     }
 }
 
+impl TryFrom<BackConfirmMsg> for Obj {
+    type Error = Error;
+
+    fn try_from(value: BackConfirmMsg) -> Result<Self, Self::Error> {
+        match value {
+            BackConfirmMsg::Back => Ok(BACK.as_obj()),
+            BackConfirmMsg::Confirmed => Ok(CONFIRMED.as_obj()),
+        }
+    }
+}
+
 impl TryFrom<CancelInfoConfirmMsg> for Obj {
     type Error = Error;
 
@@ -190,15 +201,24 @@ where
     }
 }
 
-impl<F> ComponentMsgObj for NumberInputDialog<F>
+/// Layout returned by `request_number`: the number input screen with the
+/// menu button in the header and a back button (up arrow) in the button bar.
+pub type RequestNumberScreen<F> =
+    MsgMap<Frame<NumberInputDialog<F>>, fn(FrameMsg<NumberInputDialogMsg>) -> Option<FlowMsg>>;
+
+impl<F> ComponentMsgObj for RequestNumberScreen<F>
 where
     F: Fn(u32) -> TString<'static>,
 {
     fn msg_try_into_obj(&self, msg: Self::Msg) -> Result<Obj, Error> {
-        let value = self.value();
+        // Return not only the result, but also the currently displayed number,
+        // so that Python can e.g. show the corresponding "more info" text.
+        let value = self.inner().inner().value();
         match msg {
-            NumberInputDialogMsg::Selected => Ok((CONFIRMED.as_obj(), value).try_into()?),
-            NumberInputDialogMsg::InfoRequested => Ok((INFO.as_obj(), value).try_into()?),
+            FlowMsg::Confirmed => Ok((CONFIRMED.as_obj(), value).try_into()?),
+            FlowMsg::Back => Ok((BACK.as_obj(), value).try_into()?),
+            FlowMsg::Info => Ok((INFO.as_obj(), value).try_into()?),
+            msg => msg.try_into(),
         }
     }
 }

### core/embed/rust/src/ui/layout_bolt/theme/mod.rs
@@ -56,6 +56,7 @@ include_icon!(ICON_CLICK, "layout_bolt/res/finger24.toif");
 
 include_icon!(ICON_CORNER_CANCEL, "layout_bolt/res/x32.toif");
 include_icon!(ICON_CORNER_INFO, "layout_bolt/res/info32.toif");
+include_icon!(ICON_CORNER_MENU, "layout_bolt/res/menu32.toif");
 
 // Checklist symbols.
 include_icon!(ICON_LIST_CURRENT, "layout_bolt/res/arrow-right16.toif");

### core/embed/rust/src/ui/layout_bolt/ui_firmware.rs
@@ -4,10 +4,10 @@ use core::cmp::Ordering;
 use super::component::FidoConfirm;
 use super::component::{
     check_homescreen_format, AddressDetails, Bip39Input, Button, ButtonMsg, ButtonPage,
-    ButtonStyleSheet, CancelConfirmMsg, CoinJoinProgress, Dialog, Frame, Homescreen, IconDialog,
-    Lockscreen, MnemonicKeyboard, NumberInputDialog, PassphraseKeyboard, PinKeyboard, Progress,
-    SelectMenu, SelectWordCount, SelectWordCountLayout, SetBrightnessDialog, ShareWords,
-    SimplePage, Slip39Input,
+    ButtonStyleSheet, CancelConfirmMsg, CancelInfoConfirmMsg, CoinJoinProgress, Dialog, Frame,
+    FrameMsg, Homescreen, IconDialog, Lockscreen, MnemonicKeyboard, NumberInputDialog,
+    NumberInputDialogMsg, PassphraseKeyboard, PinKeyboard, Progress, SelectMenu, SelectWordCount,
+    SelectWordCountLayout, SetBrightnessDialog, ShareWords, SimplePage, Slip39Input,
 };
 use super::{fonts, theme, UIBolt};
 use crate::io::BinaryData;
@@ -26,7 +26,7 @@ use crate::ui::component::text::paragraphs::{
 };
 use crate::ui::component::text::TextStyle;
 use crate::ui::component::{
-    Border, ComponentExt, Empty, FormattedText, Jpeg, Label, Never, Timeout,
+    Border, ComponentExt, Empty, FlowMsg, FormattedText, Jpeg, Label, Never, Timeout,
 };
 use crate::ui::layout::obj::{LayoutMaybeTrace, LayoutObj, RootComponent};
 use crate::ui::layout::util::{ConfirmValueParams, PropsList, RecoveryType};
@@ -667,11 +667,28 @@ impl FirmwareUI for UIBolt {
         more_info_callback: Option<impl Fn(u32) -> TString<'static> + 'static>,
     ) -> Result<impl LayoutMaybeTrace, Error> {
         debug_assert!(more_info_callback.is_some());
-        let layout = RootComponent::new(Frame::left_aligned(
-            theme::label_title(),
-            title,
-            NumberInputDialog::new(min_count, max_count, count, more_info_callback.unwrap())?,
-        ));
+        // The "more info" content is driven from Python: the menu button in
+        // the header emits `FlowMsg::Info` and the layout returns the
+        // currently displayed number along with the result (see
+        // `ComponentMsgObj for RequestNumberScreen`).
+        // The up-arrow button on the left goes back to the previous screen;
+        // going back is the only way out of the prompt -- interrupting the
+        // flow is not possible.
+        let map_fn: fn(FrameMsg<NumberInputDialogMsg>) -> Option<FlowMsg> = |msg| match msg {
+            FrameMsg::Content(NumberInputDialogMsg::Selected) => Some(FlowMsg::Confirmed),
+            FrameMsg::Content(NumberInputDialogMsg::Back) => Some(FlowMsg::Back),
+            FrameMsg::Button(CancelInfoConfirmMsg::Info) => Some(FlowMsg::Info),
+            _ => None,
+        };
+        let layout = RootComponent::new(
+            Frame::left_aligned(
+                theme::label_title(),
+                title,
+                NumberInputDialog::new(min_count, max_count, count, more_info_callback.unwrap())?,
+            )
+            .with_menu_button()
+            .map(map_fn),
+        );
         Ok(layout)
     }
 
@@ -819,7 +836,7 @@ impl FirmwareUI for UIBolt {
         button: TString<'static>,
         active: usize,
         items: [TString<'static>; MAX_CHECKLIST_ITEMS],
-        _back_button: bool,
+        back_button: bool,
     ) -> Result<impl LayoutMaybeTrace, Error> {
         let mut paragraphs = ParagraphVecLong::new();
         for (i, item) in items.into_iter().enumerate() {
@@ -846,9 +863,7 @@ impl FirmwareUI for UIBolt {
                 .with_check_width(theme::CHECKLIST_CHECK_WIDTH)
                 .with_current_offset(theme::CHECKLIST_CURRENT_OFFSET)
                 .with_done_offset(theme::CHECKLIST_DONE_OFFSET),
-                theme::button_bar(Button::with_text(button).map(|msg| {
-                    (matches!(msg, ButtonMsg::Clicked)).then(|| CancelConfirmMsg::Confirmed)
-                })),
+                Button::back_confirm(Button::with_text(button), back_button),
             ),
         ));
         Ok(layout)

### core/src/trezor/ui/layouts/bolt/reset.py
@@ -3,6 +3,7 @@
 import trezorui_api
 from trezor import TR
 from trezor.enums import ButtonRequestType
+from trezor.wire import ActionCancelled
 
 from ..common import interact, raise_if_not_confirmed
 
@@ -98,6 +99,7 @@ async def slip39_show_checklist(
         button=TR.buttons__continue,
         active=step,
         items=items,
+        back_button=back_button,
     ) as layout:
         return await interact(layout, "slip39_checklist", ButtonRequestType.ResetDevice)
 
@@ -110,7 +112,9 @@ async def _prompt_number(
     min_count: int,
     max_count: int,
     br_name: str,
-) -> int:
+) -> int | trezorui_api.UiResult:
+    from trezor.ui.layouts.menu import Menu, leaf_from_layout, show_menu
+
     with trezorui_api.request_number(
         title=title,
         count=count,
@@ -126,23 +130,36 @@ async def _prompt_number(
                 ButtonRequestType.ResetDevice,
                 raise_on_cancel=None,
             )
-            if __debug__:
-                if not isinstance(result, tuple):
-                    # DebugLink currently can't send number of shares and it doesn't
-                    # change the counter either so just use the initial value.
-                    result = result, count
+
+            if result is trezorui_api.CANCELLED:
+                # not reachable from the UI, only via debuglink
+                raise ActionCancelled
+
+            if __debug__ and not isinstance(result, tuple):
+                # sent by debuglink. debuglink does not change the number of
+                # shares anyway so use the initial one
+                result = (result, count)
             status, value = result
 
-            if status == CONFIRMED:
+            if status is CONFIRMED:
                 assert isinstance(value, int)
                 return value
 
-            with trezorui_api.show_simple(
-                title=None,
-                text=info(value),
-                button=TR.buttons__ok_i_understand,
-            ) as layout:
-                await interact(layout, None, raise_on_cancel=None)
+            if status is trezorui_api.BACK:
+                return trezorui_api.BACK
+
+            if status is trezorui_api.INFO:
+                # shows the menu with the "more info" screen
+                leaf = leaf_from_layout(
+                    TR.buttons__more_info,
+                    lambda: trezorui_api.show_info_with_cancel(
+                        title=title,
+                        items=[("", info(value), False)],
+                    ),
+                )
+                await show_menu(Menu([leaf]))
+            else:
+                raise RuntimeError
 
 
 def slip39_prompt_threshold(

### tests/device_tests/test_msg_backup_device.py
@@ -190,7 +190,7 @@ def test_backup_slip39_advanced(
     assert expected_ms == actual_ms
 
 
-@pytest.mark.models("safe3,delizia,eckhart")  # going back is supported on these layouts
+@pytest.mark.models("t2,safe")  # going back is supported on all core layouts
 @pytest.mark.setup_client(needs_backup=True, mnemonic=MNEMONIC_SLIP39_BASIC_20_3of6)
 def test_backup_slip39_basic_back_navigation(
     session: Session, backup_method: messages.BackupMethod
@@ -216,7 +216,7 @@ def test_backup_slip39_basic_back_navigation(
     assert expected_ms == actual_ms
 
 
-@pytest.mark.models("safe3,delizia,eckhart")  # going back is supported on these layouts
+@pytest.mark.models("t2,safe")  # going back is supported on all core layouts
 @pytest.mark.setup_client(needs_backup=True, mnemonic=MNEMONIC_SLIP39_ADVANCED_20)
 def test_backup_slip39_advanced_back_navigation(
     session: Session, backup_method: messages.BackupMethod

### tests/input_flows.py
@@ -2730,6 +2730,69 @@ def __init__(
         self.mnemonics: list[str] = []
         self.method = method
 
+    def input_flow_bolt(self) -> BRGeneratorType:
+        assert self.method in (
+            messages.BackupMethod.Display,
+            messages.BackupMethod.N1W1,
+        )
+        if self.method is messages.BackupMethod.Display:
+            assert (yield).name == "backup_intro"
+            self.debug.press_yes()
+
+        # checklist: set number of shares (no going back from the first step)
+        assert (yield).name == "slip39_checklist"
+        self.debug.press_yes()
+
+        # number of shares prompt: change the default 5 to 3
+        assert (yield).name == "slip39_shares"
+        layout = self.debug.read_layout()
+        assert layout.find_unique_value_by_key("value", None, only_type=int) == 5
+        self.debug.click(self.debug.screen_buttons.number_input_minus())
+        self.debug.click(self.debug.screen_buttons.number_input_minus())
+        self.debug.click(self.debug.screen_buttons.ok())
+
+        # checklist: set threshold -- go back via the up arrow
+        assert (yield).name == "slip39_checklist"
+        self.debug.click(self.debug.screen_buttons.cancel())
+
+        # number of shares prompt: the previously entered value is preselected
+        assert (yield).name == "slip39_shares"
+        layout = self.debug.read_layout()
+        assert layout.find_unique_value_by_key("value", None, only_type=int) == 3
+        self.debug.click(self.debug.screen_buttons.ok())
+
+        # checklist: set threshold
+        assert (yield).name == "slip39_checklist"
+        self.debug.press_yes()
+
+        # threshold prompt: increase the default 2 to 3
+        assert (yield).name == "slip39_threshold"
+        layout = self.debug.read_layout()
+        assert layout.find_unique_value_by_key("value", None, only_type=int) == 2
+        self.debug.click(self.debug.screen_buttons.number_input_plus())
+        self.debug.click(self.debug.screen_buttons.ok())
+
+        # checklist: write down the shares -- go back via the up arrow
+        assert (yield).name == "slip39_checklist"
+        self.debug.click(self.debug.screen_buttons.cancel())
+
+        # threshold prompt: the previously entered value is preselected
+        assert (yield).name == "slip39_threshold"
+        layout = self.debug.read_layout()
+        assert layout.find_unique_value_by_key("value", None, only_type=int) == 3
+        self.debug.click(self.debug.screen_buttons.ok())
+
+        # checklist: write down the shares
+        assert (yield).name == "slip39_checklist"
+        self.debug.press_yes()
+
+        if self.method is messages.BackupMethod.Display:
+            assert (yield).name == "backup_warning"
+            self.debug.press_yes()
+
+        # Mnemonic phrases
+        self.mnemonics = yield from load_N_shares(self.debug, 3, self.method)
+
     def input_flow_caesar(self) -> BRGeneratorType:
         assert self.method is messages.BackupMethod.Display
 
@@ -2962,6 +3025,95 @@ def __init__(
         self.mnemonics: list[list[str]] = []
         self.method = method
 
+    def input_flow_bolt(self) -> BRGeneratorType:
+        assert self.method in (
+            messages.BackupMethod.Display,
+            messages.BackupMethod.N1W1,
+        )
+        if self.method is messages.BackupMethod.Display:
+            assert (yield).name == "backup_intro"
+            self.debug.press_yes()
+
+        # checklist: set number of groups (no going back from the first step)
+        assert (yield).name == "slip39_checklist"
+        self.debug.press_yes()
+
+        # number of groups prompt: change the default 5 to 2
+        assert (yield).name == "slip39_groups"
+        layout = self.debug.read_layout()
+        assert layout.find_unique_value_by_key("value", None, only_type=int) == 5
+        self.debug.click(self.debug.screen_buttons.number_input_minus())
+        self.debug.click(self.debug.screen_buttons.number_input_minus())
+        self.debug.click(self.debug.screen_buttons.number_input_minus())
+        self.debug.click(self.debug.screen_buttons.ok())
+
+        # checklist: set group threshold
+        assert (yield).name == "slip39_checklist"
+        self.debug.press_yes()
+
+        # group threshold prompt: keep the default 2
+        assert (yield).name == "slip39_group_threshold"
+        layout = self.debug.read_layout()
+        assert layout.find_unique_value_by_key("value", None, only_type=int) == 2
+        self.debug.click(self.debug.screen_buttons.ok())
+
+        # checklist: set sizes and thresholds of the groups
+        assert (yield).name == "slip39_checklist"
+        self.debug.press_yes()
+
+        # group 1 shares prompt: change the default 5 to 3
+        assert (yield).name == "slip39_shares"
+        self.debug.click(self.debug.screen_buttons.number_input_minus())
+        self.debug.click(self.debug.screen_buttons.number_input_minus())
+        self.debug.click(self.debug.screen_buttons.ok())
+
+        # group 1 threshold prompt: keep the default 2
+        assert (yield).name == "slip39_threshold"
+        self.debug.click(self.debug.screen_buttons.ok())
+
+        # group 2 shares prompt: keep the default 5 -- go back via the up arrow
+        assert (yield).name == "slip39_shares"
+        self.debug.click(self.debug.screen_buttons.cancel())
+
+        # group 1 threshold prompt: the previously entered value is preselected
+        assert (yield).name == "slip39_threshold"
+        layout = self.debug.read_layout()
+        assert layout.find_unique_value_by_key("value", None, only_type=int) == 2
+        self.debug.click(self.debug.screen_buttons.ok())
+
+        # group 2 shares prompt: keep the default 5
+        assert (yield).name == "slip39_shares"
+        self.debug.click(self.debug.screen_buttons.ok())
+
+        # group 2 threshold prompt: change the default 3 to 4 -- go back
+        assert (yield).name == "slip39_threshold"
+        layout = self.debug.read_layout()
+        assert layout.find_unique_value_by_key("value", None, only_type=int) == 3
+        self.debug.click(self.debug.screen_buttons.number_input_plus())
+        self.debug.click(self.debug.screen_buttons.cancel())
+
+        # group 2 shares prompt: the previously entered value is preselected
+        assert (yield).name == "slip39_shares"
+        layout = self.debug.read_layout()
+        assert layout.find_unique_value_by_key("value", None, only_type=int) == 5
+        self.debug.click(self.debug.screen_buttons.ok())
+
+        # group 2 threshold prompt: the default 3 is shown again -- keep it
+        assert (yield).name == "slip39_threshold"
+        layout = self.debug.read_layout()
+        assert layout.find_unique_value_by_key("value", None, only_type=int) == 3
+        self.debug.click(self.debug.screen_buttons.ok())
+
+        if self.method is messages.BackupMethod.Display:
+            assert (yield).name == "backup_warning"
+            self.debug.press_yes()
+
+        # Mnemonic phrases - show & confirm shares for all groups
+        # 2 groups: 2-of-3 and 3-of-5
+        self.mnemonics = yield from load_N_groups(
+            self.debug, [(2, 3), (3, 5)], self.method
+        )
+
     def input_flow_caesar(self) -> BRGeneratorType:
         assert self.method is messages.BackupMethod.Display