diff --git a/contrib/devtools/check-deps.sh b/contrib/devtools/check-deps.sh
index 0ae817254d78..6b512deff514 100755
--- a/contrib/devtools/check-deps.sh
+++ b/contrib/devtools/check-deps.sh
@@ -47,6 +47,10 @@ declare -A SUPPRESS
 # https://github.com/bitcoin/bitcoin/issues/10102
 SUPPRESS["common.cpp.o interface_ui.cpp.o _Z11InitWarningRK13bilingual_str"]=1
 SUPPRESS["common.cpp.o interface_ui.cpp.o _Z9InitErrorRK13bilingual_str"]=1
+# CBlockHeader::GetHash() applies the CPUNET hash domain separator based on
+# the selected application chain.
+SUPPRESS["block.cpp.o args.cpp.o _ZNK11ArgsManager18GetChainTypeStringB5cxx11Ev"]=1
+SUPPRESS["block.cpp.o chaintype.cpp.o _Z17ChainTypeToStringB5cxx119ChainType"]=1
 
 usage() {
    echo "Usage: $(basename "${BASH_SOURCE[0]}") [BUILD_DIR]"
diff --git a/src/bitcoin-util.cpp b/src/bitcoin-util.cpp
index 90144cf8c807..e2edd6a8107e 100644
--- a/src/bitcoin-util.cpp
+++ b/src/bitcoin-util.cpp
@@ -134,16 +134,16 @@ static int Grind(const std::vector<std::string>& args, std::string& strPrint)
     uint16_t n_tasks = std::max(1u, std::thread::hardware_concurrency());
     if(gArgs.IsArgSet("-ntasks")) {
         const auto ntasks_str = *gArgs.GetArg("-ntasks");
-        try {
-            n_tasks = std::stoi(ntasks_str);
-            if (n_tasks <= 0 || n_tasks > std::thread::hardware_concurrency()) {
-                strPrint = strprintf("Argument to -ntasks must be a positive number less than or equal to the number of cores %u, found %s\n", std::thread::hardware_concurrency(), ntasks_str);
-                return EXIT_FAILURE;
-            }
-        } catch (const std::exception&) {
+        const auto parsed_n_tasks = ToIntegral<uint16_t>(ntasks_str);
+        if (!parsed_n_tasks) {
             strPrint = strprintf("Argument to -ntasks should be a number, found %s\n", ntasks_str);
             return EXIT_FAILURE;
         }
+        n_tasks = *parsed_n_tasks;
+        if (n_tasks <= 0 || n_tasks > std::thread::hardware_concurrency()) {
+            strPrint = strprintf("Argument to -ntasks must be a positive number less than or equal to the number of cores %u, found %s\n", std::thread::hardware_concurrency(), ntasks_str);
+            return EXIT_FAILURE;
+        }
     }
     threads.reserve(n_tasks);
     for (int i = 0; i < n_tasks; ++i) {
diff --git a/src/chainparamsbase.cpp b/src/chainparamsbase.cpp
index 125768d6d30e..83412146fef4 100644
--- a/src/chainparamsbase.cpp
+++ b/src/chainparamsbase.cpp
@@ -13,15 +13,15 @@
 
 void SetupChainParamsBaseOptions(ArgsManager& argsman)
 {
-    argsman.AddArg("-chain=<chain>", "Use the chain <chain> (default: main). Allowed values: main, test, signet, regtest, cpunet", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
+    argsman.AddArg("-chain=<chain>", "Use the chain <chain>. This build supports only regtest and cpunet.", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
     argsman.AddArg("-regtest", "Enter regression test mode, which uses a special chain in which blocks can be solved instantly. "
                  "This is intended for regression testing tools and app development. Equivalent to -chain=regtest.", ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::CHAINPARAMS);
     argsman.AddArg("-testactivationheight=name@height.", "Set the activation height of 'name' (segwit, bip34, dersig, cltv, csv). (regtest-only)", ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
-    argsman.AddArg("-testnet", "Use the testnet3 chain. Equivalent to -chain=test. Support for testnet3 is deprecated and will be removed in an upcoming release. Consider moving to testnet4 now by using -testnet4.", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
-    argsman.AddArg("-testnet4", "Use the testnet4 chain. Equivalent to -chain=testnet4.", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
+    argsman.AddArg("-testnet", "Unsupported in this build.", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
+    argsman.AddArg("-testnet4", "Unsupported in this build.", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
     argsman.AddArg("-cpunet", "Use the CPU-mined test chain. Equivalent to -chain=cpunet.", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
     argsman.AddArg("-vbparams=deployment:start:end[:min_activation_height]", "Use given start/end times and min_activation_height for specified version bits deployment (regtest-only)", ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::CHAINPARAMS);
-    argsman.AddArg("-signet", "Use the signet chain. Equivalent to -chain=signet. Note that the network is defined by the -signetchallenge parameter", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
+    argsman.AddArg("-signet", "Unsupported in this build.", ArgsManager::ALLOW_ANY, OptionsCategory::CHAINPARAMS);
     argsman.AddArg("-signetchallenge", "Blocks must satisfy the given script to be considered valid (only for signet networks; defaults to the global default signet test network challenge)", ArgsManager::ALLOW_ANY | ArgsManager::DISALLOW_NEGATION, OptionsCategory::CHAINPARAMS);
     argsman.AddArg("-signetseednode", "Specify a seed node for the signet network, in the hostname[:port] format, e.g. sig.net:1234 (may be used multiple times to specify multiple seed nodes; defaults to the global default signet test network seed node(s))", ArgsManager::ALLOW_ANY | ArgsManager::DISALLOW_NEGATION, OptionsCategory::CHAINPARAMS);
 }
diff --git a/src/chainparamsbase.h b/src/chainparamsbase.h
index 0700b9ae2e71..ab417dd1d58c 100644
--- a/src/chainparamsbase.h
+++ b/src/chainparamsbase.h
@@ -25,7 +25,7 @@ class CBaseChainParams
     uint16_t OnionServiceTargetPort() const { return m_onion_service_target_port; }
     CBaseChainParams() = delete;
     CBaseChainParams(const std::string& data_dir, uint16_t rpc_port, uint16_t onion_service_target_port)
-        : m_rpc_port(rpc_port), strDataDir(data_dir), m_onion_service_target_port(onion_service_target_port) {}
+        : m_rpc_port(rpc_port), m_onion_service_target_port(onion_service_target_port), strDataDir(data_dir) {}
 
 private:
     const uint16_t m_rpc_port;
diff --git a/src/kernel/CMakeLists.txt b/src/kernel/CMakeLists.txt
index 244f0098fdf9..7960fb12f958 100644
--- a/src/kernel/CMakeLists.txt
+++ b/src/kernel/CMakeLists.txt
@@ -107,6 +107,7 @@ target_link_libraries(bitcoinkernel
     $<TARGET_NAME_IF_EXISTS:USDT::headers>
     Boost::headers
 )
+target_compile_definitions(bitcoinkernel PRIVATE BITCOIN_KERNEL)
 
 target_include_directories(bitcoinkernel PRIVATE $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/src/leveldb/include>)
 
diff --git a/src/kernel/chainparams.cpp b/src/kernel/chainparams.cpp
index fdea3ad8a4b8..d84fd77cb157 100644
--- a/src/kernel/chainparams.cpp
+++ b/src/kernel/chainparams.cpp
@@ -16,7 +16,6 @@
 #include <primitives/transaction.h>
 #include <script/interpreter.h>
 #include <script/script.h>
-#include <streams.h>
 #include <uint256.h>
 #include <util/chaintype.h>
 #include <util/log.h>
@@ -27,6 +26,7 @@
 #include <cassert>
 #include <cstdint>
 #include <cstring>
+#include <initializer_list>
 #include <iterator>
 #include <map>
 #include <span>
@@ -478,7 +478,7 @@ class CCPUNetParams : public CChainParams {
         m_assumed_chain_state_size = 0;
 
         const char* cpunet_genesis_msg = "03/May/2024 000000000000000000001ebd58c244970b3aa9d783bb001011fbe8ea8e98e00e";
-        const CScript cpunet_genesis_script = CScript() << ParseHex("000000000000000000000000000000000000000000000000000000000000000000") << OP_CHECKSIG;
+        const CScript cpunet_genesis_script = CScript() << "000000000000000000000000000000000000000000000000000000000000000000"_hex << OP_CHECKSIG;
         genesis = CreateGenesisBlock(cpunet_genesis_msg,
                 cpunet_genesis_script,
                 1723652721,
@@ -486,9 +486,7 @@ class CCPUNetParams : public CChainParams {
                 0x1d00ffff,
                 1,
                 50 * COIN);
-        consensus.hashGenesisBlock = genesis.GetHash();
-        //std::cerr << "CPUNet Genesis Block header: "
-        //    << HexStr(DataStream{} << genesis.GetBlockHeader() << "cpunet") << std::endl;
+        consensus.hashGenesisBlock = (HashWriter{} << static_cast<const CBlockHeader&>(genesis) << "cpunet").GetHash();
         assert(consensus.hashGenesisBlock == uint256("0x00000000bbffa57733938dbc05f86239f303636de4599905ab84bccfa909f49b"));
         assert(genesis.hashMerkleRoot == uint256("0x7aa0a7ae1e223414cb807e40cd57e667b718e42aaf9306db9102fe28912b7b4e"));
 
@@ -617,7 +615,7 @@ class SigNetParams : public CChainParams {
 
         genesis = CreateGenesisBlock(1598918400, 52613770, 0x1e0377ae, 1, 50 * COIN);
         consensus.hashGenesisBlock = genesis.GetHash();
-        //assert(consensus.hashGenesisBlock == uint256{"00000008819873e925422c1ff0f99f7cc9bbb232af63a077a480a3633bee1ef6"});
+        assert(consensus.hashGenesisBlock == uint256{"00000008819873e925422c1ff0f99f7cc9bbb232af63a077a480a3633bee1ef6"});
         assert(genesis.hashMerkleRoot == uint256{"4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"});
 
         m_assumeutxo_data = {
@@ -844,6 +842,8 @@ std::optional<ChainType> GetNetworkForMagic(const MessageStartChars& message)
         return ChainType::MAIN;
     } else if (std::ranges::equal(message, testnet_msg)) {
         return ChainType::TESTNET;
+    } else if (std::ranges::equal(message, testnet4_msg)) {
+        return ChainType::TESTNET4;
     } else if (std::equal(message.begin(), message.end(), cpunet_msg.data())) {
         return ChainType::CPUNET;
     } else if (std::equal(message.begin(), message.end(), regtest_msg.data())) {
diff --git a/src/primitives/block.cpp b/src/primitives/block.cpp
index 24945ee4398c..4a3eec4f22f1 100644
--- a/src/primitives/block.cpp
+++ b/src/primitives/block.cpp
@@ -5,8 +5,10 @@
 
 #include <primitives/block.h>
 
+#include <common/args.h>
 #include <hash.h>
 #include <tinyformat.h>
+#include <util/chaintype.h>
 
 #include <memory>
 #include <span>
@@ -14,7 +16,12 @@
 
 uint256 CBlockHeader::GetHash() const
 {
-    return (HashWriter{} << *this << "cpunet").GetHash();
+#ifndef BITCOIN_KERNEL
+    if (gArgs.GetChainTypeString() == ChainTypeToString(ChainType::CPUNET)) {
+        return (HashWriter{} << *this << "cpunet").GetHash();
+    }
+#endif
+    return (HashWriter{} << *this).GetHash();
 }
 
 std::string CBlock::ToString() const
diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
index 1619227a419f..2c8ee51bf3d7 100644
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -118,6 +118,9 @@ static std::string DummyAddress(const CChainParams &params)
     case ChainType::TESTNET4:
         addr = "tb1p35yvjel7srp783ztf8v6jdra7dhfzk5jaun8xz2qp6ws7z80n4tqa6qnlg";
         break;
+    case ChainType::CPUNET:
+        addr = "tc1p35yvjel7srp783ztf8v6jdra7dhfzk5jaun8xz2qp6ws7z80n4tqsr2427";
+        break;
     case ChainType::REGTEST:
         addr = "bcrt1p35yvjel7srp783ztf8v6jdra7dhfzk5jaun8xz2qp6ws7z80n4tqsr2427";
         break;
diff --git a/src/test/argsman_tests.cpp b/src/test/argsman_tests.cpp
index e91ae5e96f3a..2d853dba0129 100644
--- a/src/test/argsman_tests.cpp
+++ b/src/test/argsman_tests.cpp
@@ -1019,7 +1019,7 @@ BOOST_FIXTURE_TEST_CASE(util_ChainMerge, ChainMergeTestingSetup)
     // Results file is formatted like:
     //
     //   <input> || <output>
-    BOOST_CHECK_EQUAL(out_sha_hex, "c0e33aab0c74e040ddcee9edad59e8148d8e1cacb3cccd9ea1a1f485cb6bad21");
+    BOOST_CHECK_EQUAL(out_sha_hex, "10e719bafb214ffd48840299719ccc651beb38609e707387e893ba38982be3d5");
 }
 
 BOOST_AUTO_TEST_CASE(util_ReadWriteSettings)
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
index 298edf880246..bd9cf2384418 100755
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -233,6 +233,7 @@
     'p2p_addrfetch.py',
     'rpc_net.py --v1transport',
     'rpc_net.py --v2transport',
+    'rpc_mempool_info.py',
     'wallet_keypool.py',
     'wallet_descriptor.py',
     'p2p_nobloomfilter_messages.py',