diff --git a/test/functional/feature_framework_startup_failures.py b/test/functional/feature_framework_startup_failures.py
index d6da7f713b..84a7d9d837 100755
--- a/test/functional/feature_framework_startup_failures.py
+++ b/test/functional/feature_framework_startup_failures.py
@@ -36,15 +36,11 @@ class FeatureFrameworkStartupFailures(BitcoinTestFramework):
     # Launches a child test process that runs this same file, but instantiates
     # a child test. Verifies that it raises only the expected exception, once.
     def _verify_startup_failure(self, test, internal_args, expected_exception):
-        # Inherit args from parent, only modifying tmpdir so children don't fail
-        # as a cause of colliding with the parent dir.
-        parent_args = sys.argv.copy()
+        # Inherit sys.argv from parent, only overriding tmpdir to a subdirectory
+        # so children don't fail due to colliding with the parent dir.
         assert self.options.tmpdir, "Framework should always set tmpdir."
-        i, path = next(((i, m[1]) for i, arg in enumerate(parent_args) if (m := re.match(r'--tm(?:p(?:d(?:ir?)?)?)?=(.+)', arg))),
-                       (len(parent_args), self.options.tmpdir))
         subdir = md5(expected_exception.encode('utf-8')).hexdigest()[:8]
-        parent_args[i:i + 1] = [f"--tmpdir={path}/{subdir}"]
-        args = [sys.executable] + parent_args + [f"--internal_test={test.__name__}"] + internal_args
+        args = [sys.executable] + sys.argv + [f"--tmpdir={self.options.tmpdir}/{subdir}", f"--internal_test={test.__name__}"] + internal_args
 
         try:
             # The subprocess encoding argument gives different results for e.output
@@ -73,10 +69,10 @@ class FeatureFrameworkStartupFailures(BitcoinTestFramework):
         self.log.info("Verifying _verify_startup_failure() functionality (self-check).")
         assert_raises_message(
             AssertionError,
-            ("Child test didn't contain (only) expected errors:\n" +
-             linesep.join(["Found 0/1 tracebacks - expecting exactly one with no knock-on exceptions.",
-                           "Found 0/1 occurrences of the specific exception: NonExistentError",
-                           "Found 0/1 test failure output messages."])).encode("unicode_escape").decode("utf-8"),
+            ( "Child test didn't contain (only) expected errors:\n"
+             f"Found 0/1 tracebacks - expecting exactly one with no knock-on exceptions.{linesep}"
+             f"Found 0/1 occurrences of the specific exception: NonExistentError{linesep}"
+              "Found 0/1 test failure output messages."),
             self._verify_startup_failure,
             TestSuccess, [],
             "NonExistentError",
@@ -93,7 +89,7 @@ class FeatureFrameworkStartupFailures(BitcoinTestFramework):
         self.log.info("Verifying inability to connect to bitcoind's RPC interface due to wrong port results in one exception containing at least one OSError.")
         self._verify_startup_failure(
             TestWrongRpcPortStartupFailure, [f"--internal_node_start_duration={node_start_duration}"],
-            r"AssertionError: \[node 0\] Unable to connect to bitcoind after \d+s \(ignored errors: {[^}]*'OSError \w+'?: \d+[^}]*}, latest error: \w+\([^)]+\)\)"
+            r"AssertionError: \[node 0\] Unable to connect to bitcoind after \d+s \(ignored errors: {[^}]*'OSError \w+'?: \d+[^}]*}, latest: '[\w ]+'/\w+\([^)]+\)\)"
         )
 
         self.log.info("Verifying startup failure due to invalid arg results in only one exception.")
diff --git a/test/functional/test_framework/test_framework.py b/test/functional/test_framework/test_framework.py
index 479263d967..ce341891aa 100755
--- a/test/functional/test_framework/test_framework.py
+++ b/test/functional/test_framework/test_framework.py
@@ -267,7 +267,7 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
         parser.add_argument("-f", "--fff", help="a dummy argument to fool ipython", default="1")
         self.options = parser.parse_args()
         if self.options.timeout_factor == 0:
-            self.options.timeout_factor = 99999
+            self.options.timeout_factor = 999
         self.options.timeout_factor = self.options.timeout_factor or (4 if self.options.valgrind else 1)
         self.options.previous_releases_path = previous_releases_path
 
diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
index e36bad589d..10d5337ea0 100755
--- a/test/functional/test_framework/test_node.py
+++ b/test/functional/test_framework/test_node.py
@@ -262,8 +262,13 @@ class TestNode():
         """Sets up an RPC connection to the bitcoind process. Returns False if unable to connect."""
         # Poll at a rate of four times per second
         poll_per_s = 4
+
         suppressed_errors = collections.defaultdict(int)
-        latest_error = ""
+        latest_error = None
+        def suppress_error(category: str, e: Exception):
+            suppressed_errors[category] += 1
+            return (category, repr(e))
+
         for _ in range(poll_per_s * self.rpc_timeout):
             if self.process.poll() is not None:
                 # Attach abrupt shutdown error/s to the exception message
@@ -317,8 +322,7 @@ class TestNode():
                 # -342 Service unavailable, could be starting up or shutting down
                 if e.error['code'] not in [-28, -342]:
                     raise  # unknown JSON RPC exception
-                suppressed_errors[f"JSONRPCException {e.error['code']}"] += 1
-                latest_error = repr(e)
+                latest_error = suppress_error(f"JSONRPCException {e.error['code']}", e)
             except OSError as e:
                 error_num = e.errno
                 # Work around issue where socket timeouts don't have errno set.
@@ -334,16 +338,14 @@ class TestNode():
                     errno.ECONNREFUSED  # Port not yet open?
                 ]:
                     raise  # unknown OS error
-                suppressed_errors[f"OSError {errno.errorcode[error_num]}"] += 1
-                latest_error = repr(e)
+                latest_error = suppress_error(f"OSError {errno.errorcode[error_num]}", e)
             except ValueError as e:
                 # Suppress if cookie file isn't generated yet and no rpcuser or rpcpassword; bitcoind may be starting.
                 if "No RPC credentials" not in str(e):
                     raise
-                suppressed_errors["missing_credentials"] += 1
-                latest_error = repr(e)
+                latest_error = suppress_error("missing_credentials", e)
             time.sleep(1.0 / poll_per_s)
-        self._raise_assertion_error(f"Unable to connect to bitcoind after {self.rpc_timeout}s (ignored errors: {str(dict(suppressed_errors))}, latest error: {latest_error})")
+        self._raise_assertion_error(f"Unable to connect to bitcoind after {self.rpc_timeout}s (ignored errors: {dict(suppressed_errors)!s}{'' if latest_error is None else f', latest: {latest_error[0]!r}/{latest_error[1]}'})")
 
     def wait_for_cookie_credentials(self):
         """Ensures auth cookie credentials can be read, e.g. for testing CLI with -rpcwait before RPC connection is up."""
diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
index ab120b7710..e5a5938f07 100644
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -102,9 +102,9 @@ def assert_raises_message(exc, message, fun, *args, **kwds):
     except JSONRPCException:
         raise AssertionError("Use assert_raises_rpc_error() to test RPC failures")
     except exc as e:
-        if message is not None and message not in repr(e):
+        if message is not None and message not in str(e):
             raise AssertionError("Expected substring not found in exception:\n"
-                                 f"substring: '{message}'\nexception: {repr(e)}.")
+                                 f"substring: '{message}'\nexception: {e!r}.")
     except Exception as e:
         raise AssertionError("Unexpected exception raised: " + type(e).__name__)
     else: