test: misc interface_ipc_mining.py improvements

diff --git a/test/functional/interface_ipc_mining.py b/test/functional/interface_ipc_mining.py
index b12dd9c8..20f90490 100755
--- a/test/functional/interface_ipc_mining.py
+++ b/test/functional/interface_ipc_mining.py
@@ -131,7 +131,7 @@ class IPCMiningTest(BitcoinTestFramework):
             ctx, mining = await self.make_mining_ctx()
             blockref = await mining.getTip(ctx)
             current_block_height = self.nodes[0].getchaintips()[0]["height"]
-            assert blockref.result.height == current_block_height
+            assert_equal(blockref.result.height, current_block_height)
 
             self.log.debug("Mine a block")
             newblockref = (await wait_and_do(
@@ -152,7 +152,6 @@ class IPCMiningTest(BitcoinTestFramework):
         self.log.info("Running BlockTemplate interface test")
         block_header_size = 80
         timeout = 1000.0 # 1000 milliseconds
-        miniwallet = MiniWallet(self.nodes[0])
 
         async def async_routine():
             ctx, mining = await self.make_mining_ctx()
@@ -160,11 +159,7 @@ class IPCMiningTest(BitcoinTestFramework):
 
             async with AsyncExitStack() as stack:
                 self.log.debug("Create a template")
-                opts = self.capnp_modules['mining'].BlockCreateOptions()
-                opts.useMempool = True
-                opts.blockReservedWeight = 4000
-                opts.coinbaseOutputMaxAdditionalSigops = 0
-                template = await mining_create_block_template(mining, stack, ctx, opts)
+                template = await mining_create_block_template(mining, stack, ctx, self.default_block_create_options)
 
                 self.log.debug("Test some inspectors of Template")
                 header = (await template.getBlockHeader(ctx)).result
@@ -194,7 +189,7 @@ class IPCMiningTest(BitcoinTestFramework):
                 self.log.debug("Wait for another, get one after increase in fees in the mempool")
                 template4 = await wait_and_do(
                     mining_wait_next_template(template2, stack, ctx, waitoptions),
-                    lambda: miniwallet.send_self_transfer(fee_rate=10, from_node=self.nodes[0]))
+                    lambda: self.miniwallet.send_self_transfer(fee_rate=10, from_node=self.nodes[0]))
                 block3 = await mining_get_block(template4, ctx)
                 assert_equal(len(block3.vtx), 2)
 
@@ -208,7 +203,7 @@ class IPCMiningTest(BitcoinTestFramework):
                 self.log.debug("Wait for another, get one after increase in fees in the mempool")
                 template6 = await wait_and_do(
                     mining_wait_next_template(template5, stack, ctx, waitoptions),
-                    lambda: miniwallet.send_self_transfer(fee_rate=10, from_node=self.nodes[0]))
+                    lambda: self.miniwallet.send_self_transfer(fee_rate=10, from_node=self.nodes[0]))
                 block4 = await mining_get_block(template6, ctx)
                 assert_equal(len(block4.vtx), 3)
 
@@ -219,7 +214,7 @@ class IPCMiningTest(BitcoinTestFramework):
                 self.log.debug("interruptWait should abort the current wait")
                 async def wait_for_block():
                     new_waitoptions = self.capnp_modules['mining'].BlockWaitOptions()
-                    new_waitoptions.timeout = waitoptions.timeout * 60 # 1 minute wait
+                    new_waitoptions.timeout = timeout * 60 # 1 minute wait
                     new_waitoptions.feeThreshold = 1
                     template7 = await template6.waitNext(ctx, new_waitoptions)
                     assert_equal(template7._has("result"), False)
@@ -235,17 +230,12 @@ class IPCMiningTest(BitcoinTestFramework):
             ctx, mining = await self.make_mining_ctx()
 
             current_block_height = self.nodes[0].getchaintips()[0]["height"]
-            miniwallet = MiniWallet(self.nodes[0])
-            opts = self.capnp_modules['mining'].BlockCreateOptions()
-            opts.useMempool = True
-            opts.blockReservedWeight = 4000
-            opts.coinbaseOutputMaxAdditionalSigops = 0
             check_opts = self.capnp_modules['mining'].BlockCheckOptions()
 
-            async with destroying((await mining.createNewBlock(opts)).result, ctx) as template:
+            async with destroying((await mining.createNewBlock(self.default_block_create_options)).result, ctx) as template:
                 block = await mining_get_block(template, ctx)
-                balance = miniwallet.get_balance()
-                coinbase = await self.build_coinbase_test(template, ctx, miniwallet)
+                balance = self.miniwallet.get_balance()
+                coinbase = await self.build_coinbase_test(template, ctx, self.miniwallet)
                 # Reduce payout for balance comparison simplicity
                 coinbase.vout[0].nValue = COIN
                 block.vtx[0] = coinbase
@@ -276,7 +266,7 @@ class IPCMiningTest(BitcoinTestFramework):
                 submitted = (await template.submitSolution(ctx, block.nVersion, block.nTime, block.nNonce, coinbase.serialize_without_witness())).result
                 assert_equal(submitted, False)
 
-                self.log.debug("Even a rejected submitBlock() mutates the template's block")
+                self.log.debug("Even a rejected submitSolution() mutates the template's block")
                 # Can be used by clients to download and inspect the (rejected)
                 # reconstructed block.
                 remote_block_after = await mining_get_block(template, ctx)
@@ -289,13 +279,13 @@ class IPCMiningTest(BitcoinTestFramework):
             self.log.debug("Block should propagate")
             # Check that the IPC node actually updates its own chain
             assert_equal(self.nodes[0].getchaintips()[0]["height"], current_block_height + 1)
-            # Stalls if a regression causes submitBlock() to accept an invalid block:
+            # Stalls if a regression causes submitSolution() to accept an invalid block:
             self.sync_all()
             # Check that the other node accepts the block
             assert_equal(self.nodes[0].getchaintips()[0], self.nodes[1].getchaintips()[0])
 
-            miniwallet.rescan_utxos()
-            assert_equal(miniwallet.get_balance(), balance + 1)
+            self.miniwallet.rescan_utxos()
+            assert_equal(self.miniwallet.get_balance(), balance + 1)
             self.log.debug("Check block should fail now, since it is a duplicate")
             check = await mining.checkBlock(block.serialize(), check_opts)
             assert_equal(check.result, False)
@@ -304,6 +294,13 @@ class IPCMiningTest(BitcoinTestFramework):
         asyncio.run(capnp.run(async_routine()))
 
     def run_test(self):
+        self.miniwallet = MiniWallet(self.nodes[0])
+        self.default_block_create_options = self.capnp_modules['mining'].BlockCreateOptions(
+            useMempool=True,
+            blockReservedWeight=4000,
+            coinbaseOutputMaxAdditionalSigops=0
+        )
+
         self.run_mining_interface_test()
         self.run_block_template_test()
         self.run_coinbase_and_submission_test()