diff --git a/requirements/dev.txt b/requirements/dev.txt
index 93fe986551..485c595299 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -363,7 +363,7 @@ django-sessionprofile==2.0.0
     #   -c requirements/ci.txt
     #   -r requirements/ci.txt
     #   django-digid-eherkenning
-django-silk==5.1.0
+django-silk==5.2.0
     # via -r requirements/dev.in
 django-simple-certmanager==2.4.1
     # via
diff --git a/src/openforms/formio/datastructures.py b/src/openforms/formio/datastructures.py
index 848b2855fb..33119ee36d 100644
--- a/src/openforms/formio/datastructures.py
+++ b/src/openforms/formio/datastructures.py
@@ -1,6 +1,5 @@
 import re
 from collections import UserDict
-from collections.abc import Hashable
 from typing import Iterator, cast
 
 from glom import PathAccessError, assign, glom
@@ -162,16 +161,42 @@ class FormioData(UserDict):
     """
 
     data: dict[str, JSONValue]
+    _keys: set[str]
+    """
+    A collection of flattened key names, for quicker __contains__ access
+    """
 
-    def __getitem__(self, key: Hashable):
+    def __init__(self, *args, **kwargs):
+        self._keys = set()
+        super().__init__(*args, **kwargs)
+
+    def __getitem__(self, key: str):
+        if "." not in key:
+            return self.data[key]
         return cast(JSONValue, glom(self.data, key))
 
-    def __setitem__(self, key: Hashable, value: JSONValue):
+    def __setitem__(self, key: str, value: JSONValue):
         assign(self.data, key, value, missing=dict)
+        self._keys.add(key)
+
+    def __contains__(self, key: object) -> bool:
+        """
+        Check if the key is present in the data container.
+
+        This gets called via ``formio_data.get(...)`` to check if the default needs to
+        be returned or not. Keys are expected to be strings taken from ``variable.key``
+        fields.
+        """
+        if not isinstance(key, str):
+            raise TypeError("Only string keys are supported")
+
+        # for direct keys, we can optimize access and bypass glom + its exception
+        # throwing.
+        if "." not in key:
+            return key in self._keys
 
-    def __contains__(self, key: Hashable) -> bool:
         try:
             self[key]
+            return True
         except PathAccessError:
             return False
-        return True
diff --git a/src/openforms/formio/tests/test_datastructures.py b/src/openforms/formio/tests/test_datastructures.py
index 5d82629a9f..374380006a 100644
--- a/src/openforms/formio/tests/test_datastructures.py
+++ b/src/openforms/formio/tests/test_datastructures.py
@@ -89,6 +89,20 @@ def test_initializing_with_dotted_paths_expands(self):
 
         self.assertEqual(formio_data, expected)
 
+    def test_key_access_must_be_string(self):
+        formio_data = FormioData({"foo": "bar"})
+
+        bad_keys = (
+            3,
+            None,
+            4.3,
+            ("foo",),
+        )
+
+        for key in bad_keys:
+            with self.assertRaises(TypeError):
+                key in formio_data  # type: ignore
+
 
 class FormioConfigurationWrapperTests(TestCase):
 
diff --git a/src/openforms/registrations/contrib/objects_api/submission_registration.py b/src/openforms/registrations/contrib/objects_api/submission_registration.py
index 4523575702..7734035e1a 100644
--- a/src/openforms/registrations/contrib/objects_api/submission_registration.py
+++ b/src/openforms/registrations/contrib/objects_api/submission_registration.py
@@ -9,7 +9,6 @@
 from django.db.models import F
 
 import glom
-from glom import PathAccessError
 
 from openforms.authentication.service import AuthAttribute
 from openforms.contrib.objects_api.clients import (
@@ -537,7 +536,7 @@ def get_record_data(
         for key, variable in state.variables.items():
             try:
                 submission_value = dynamic_values[key]
-            except PathAccessError:
+            except KeyError:
                 continue
 
             # special casing documents - we transform the formio file upload data into