diff --git a/doc/python_api/rst/info_quickstart.rst b/doc/python_api/rst/info_quickstart.rst
index 4e7382b9dd6..d422bd9b656 100644
--- a/doc/python_api/rst/info_quickstart.rst
+++ b/doc/python_api/rst/info_quickstart.rst
@@ -447,9 +447,22 @@ Using low-level functions:
 .. code-block:: python
 
    obj = bpy.context.object
-   obj.animation_data_create()
-   obj.animation_data.action = bpy.data.actions.new(name="MyAction")
-   fcu_z = obj.animation_data.action.fcurves.new(data_path="location", index=2)
+
+   # Create the action, with a slot for the object, a layer, and a keyframe strip:
+   action = bpy.data.actions.new(name="MyAction")
+   slot = action.slots.new(obj.id_type, obj.name)
+   strip = action.layers.new("MyLayer").strips.new(type='KEYFRAME')
+
+   # Create a channelbag to hold the F-Curves for the slot:
+   channelbag = strip.channelbag(slot, ensure=True)
+
+   # Create the F-Curve with two keyframes:
+   fcu_z = channelbag.fcurves.new(data_path="location", index=2)
    fcu_z.keyframe_points.add(2)
    fcu_z.keyframe_points[0].co = 10.0, 0.0
    fcu_z.keyframe_points[1].co = 20.0, 1.0
+
+   # Assign the action and the slot to the object:
+   adt = obj.animation_data_create()
+   adt.action = action
+   adt.action_slot = slot
diff --git a/source/blender/bmesh/intern/bmesh_operator_api.hh b/source/blender/bmesh/intern/bmesh_operator_api.hh
index f36c924e404..983cc3e3cfe 100644
--- a/source/blender/bmesh/intern/bmesh_operator_api.hh
+++ b/source/blender/bmesh/intern/bmesh_operator_api.hh
@@ -12,7 +12,6 @@
 #include "BLI_utildefines.h"
 
 #include <cstdarg>
-#include <optional>
 
 #include "bmesh_class.hh"
 
@@ -240,15 +239,6 @@ union eBMOpSlotSubType_Union {
   eBMOpSlotSubType_Int intg;
 };
 
-enum eBMOpSlotFlag : uint8_t {
-  /**
-   * This flag is set when the operators value has been set.
-   * Use this so it's possible to have non-zero defaults for properties.
-   */
-  BMO_OP_SLOT_FLAG_IS_SET = (1 << 0),
-};
-ENUM_OPERATORS(eBMOpSlotFlag, BMO_OP_SLOT_FLAG_IS_SET)
-
 struct BMO_FlagSet {
   int value;
   const char *identifier;
@@ -262,8 +252,8 @@ struct BMOpSlot {
   eBMOpSlotType slot_type;
   eBMOpSlotSubType_Union slot_subtype;
 
-  eBMOpSlotFlag flag;
   int len;
+  //  int flag;  /* UNUSED */
   //  int index; /* index within slot array */  /* UNUSED */
   union {
     int i;
@@ -559,16 +549,10 @@ void BMO_op_flag_disable(BMesh *bm, BMOperator *op, int op_flag);
 
 void BMO_slot_float_set(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name, float f);
 float BMO_slot_float_get(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name);
-std::optional<float> BMO_slot_float_get_optional(BMOpSlot slot_args[BMO_OP_MAX_SLOTS],
-                                                 const char *slot_name);
 void BMO_slot_int_set(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name, int i);
 int BMO_slot_int_get(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name);
-std::optional<int> BMO_slot_int_get_optional(BMOpSlot slot_args[BMO_OP_MAX_SLOTS],
-                                             const char *slot_name);
 void BMO_slot_bool_set(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name, bool i);
 bool BMO_slot_bool_get(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name);
-std::optional<bool> BMO_slot_bool_get_optional(BMOpSlot slot_args[BMO_OP_MAX_SLOTS],
-                                               const char *slot_name);
 /**
  * Return a copy of the element buffer.
  */
diff --git a/source/blender/bmesh/intern/bmesh_operators.cc b/source/blender/bmesh/intern/bmesh_operators.cc
index d93dc25ac26..d56a9b80f5a 100644
--- a/source/blender/bmesh/intern/bmesh_operators.cc
+++ b/source/blender/bmesh/intern/bmesh_operators.cc
@@ -295,8 +295,6 @@ void _bmo_slot_copy(BMOpSlot slot_args_src[BMO_OP_MAX_SLOTS],
   else {
     slot_dst->data = slot_src->data;
   }
-
-  slot_dst->flag = slot_src->flag;
 }
 
 /*
@@ -314,7 +312,6 @@ void BMO_slot_float_set(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_n
   }
 
   slot->data.f = f;
-  slot->flag |= BMO_OP_SLOT_FLAG_IS_SET;
 }
 
 void BMO_slot_int_set(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name, const int i)
@@ -326,7 +323,6 @@ void BMO_slot_int_set(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_nam
   }
 
   slot->data.i = i;
-  slot->flag |= BMO_OP_SLOT_FLAG_IS_SET;
 }
 
 void BMO_slot_bool_set(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name, const bool i)
@@ -338,7 +334,6 @@ void BMO_slot_bool_set(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_na
   }
 
   slot->data.i = i;
-  slot->flag |= BMO_OP_SLOT_FLAG_IS_SET;
 }
 
 void BMO_slot_mat_set(BMOperator *op,
@@ -367,7 +362,6 @@ void BMO_slot_mat_set(BMOperator *op,
 
     zero_m4(static_cast<float(*)[4]>(slot->data.p));
   }
-  slot->flag |= BMO_OP_SLOT_FLAG_IS_SET;
 }
 
 void BMO_slot_mat4_get(BMOpSlot slot_args[BMO_OP_MAX_SLOTS],
@@ -415,7 +409,6 @@ void BMO_slot_ptr_set(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_nam
   }
 
   slot->data.p = p;
-  slot->flag |= BMO_OP_SLOT_FLAG_IS_SET;
 }
 
 void BMO_slot_vec_set(BMOpSlot slot_args[BMO_OP_MAX_SLOTS],
@@ -429,51 +422,31 @@ void BMO_slot_vec_set(BMOpSlot slot_args[BMO_OP_MAX_SLOTS],
   }
 
   copy_v3_v3(slot->data.vec, vec);
-  slot->flag |= BMO_OP_SLOT_FLAG_IS_SET;
 }
 
 float BMO_slot_float_get(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name)
-{
-  return BMO_slot_float_get_optional(slot_args, slot_name).value_or(0.0f);
-}
-
-std::optional<float> BMO_slot_float_get_optional(BMOpSlot slot_args[BMO_OP_MAX_SLOTS],
-                                                 const char *slot_name)
 {
   BMOpSlot *slot = BMO_slot_get(slot_args, slot_name);
   BLI_assert(slot->slot_type == BMO_OP_SLOT_FLT);
   if (!(slot->slot_type == BMO_OP_SLOT_FLT)) {
-    return std::nullopt;
-  }
-  if ((slot->flag & BMO_OP_SLOT_FLAG_IS_SET) == 0) {
-    return std::nullopt;
+    return 0.0f;
   }
 
   return slot->data.f;
 }
 
-std::optional<int> BMO_slot_int_get_optional(BMOpSlot slot_args[BMO_OP_MAX_SLOTS],
-                                             const char *slot_name)
+int BMO_slot_int_get(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name)
 {
   BMOpSlot *slot = BMO_slot_get(slot_args, slot_name);
   BLI_assert(slot->slot_type == BMO_OP_SLOT_INT);
   if (!(slot->slot_type == BMO_OP_SLOT_INT)) {
-    return std::nullopt;
-  }
-  if ((slot->flag & BMO_OP_SLOT_FLAG_IS_SET) == 0) {
-    return std::nullopt;
+    return 0;
   }
 
   return slot->data.i;
 }
 
-int BMO_slot_int_get(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name)
-{
-  return BMO_slot_int_get_optional(slot_args, slot_name).value_or(0);
-}
-
-std::optional<bool> BMO_slot_bool_get_optional(BMOpSlot slot_args[BMO_OP_MAX_SLOTS],
-                                               const char *slot_name)
+bool BMO_slot_bool_get(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name)
 {
   BMOpSlot *slot = BMO_slot_get(slot_args, slot_name);
   BLI_assert(slot->slot_type == BMO_OP_SLOT_BOOL);
@@ -483,10 +456,6 @@ std::optional<bool> BMO_slot_bool_get_optional(BMOpSlot slot_args[BMO_OP_MAX_SLO
 
   return slot->data.i;
 }
-bool BMO_slot_bool_get(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name)
-{
-  return BMO_slot_bool_get_optional(slot_args, slot_name).value_or(false);
-}
 
 void *BMO_slot_as_arrayN(BMOpSlot slot_args[BMO_OP_MAX_SLOTS], const char *slot_name, int *len)
 {
diff --git a/source/blender/bmesh/operators/bmo_dissolve.cc b/source/blender/bmesh/operators/bmo_dissolve.cc
index b0ea5877f5a..f377a0dd269 100644
--- a/source/blender/bmesh/operators/bmo_dissolve.cc
+++ b/source/blender/bmesh/operators/bmo_dissolve.cc
@@ -387,9 +387,7 @@ void bmo_dissolve_edges_exec(BMesh *bm, BMOperator *op)
    * This lets the test ignore that tiny bit of math error so users won't notice. */
   const float angle_epsilon = RAD2DEGF(0.0001f);
 
-  /* When unset, don't limit dissolving vertices at all. */
-  const float angle_threshold =
-      BMO_slot_float_get_optional(op->slots_in, "angle_threshold").value_or(M_PI);
+  const float angle_threshold = BMO_slot_float_get(op->slots_in, "angle_threshold");
 
   /* Use verts when told to... except, do *not* use verts when angle_threshold is 0.0. */
   const bool use_verts = BMO_slot_bool_get(op->slots_in, "use_verts") &&
diff --git a/tests/python/CMakeLists.txt b/tests/python/CMakeLists.txt
index 44ff11f9b46..0c1240cb523 100644
--- a/tests/python/CMakeLists.txt
+++ b/tests/python/CMakeLists.txt
@@ -261,6 +261,11 @@ add_blender_test(
   --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_text.py
 )
 
+add_blender_test(
+  script_pyapi_bmesh
+  --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_bmesh.py
+)
+
 add_blender_test(
   script_pyapi_grease_pencil
   --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_grease_pencil.py
diff --git a/tests/python/bl_pyapi_bmesh.py b/tests/python/bl_pyapi_bmesh.py
new file mode 100644
index 00000000000..3a7d4e4c5fe
--- /dev/null
+++ b/tests/python/bl_pyapi_bmesh.py
@@ -0,0 +1,31 @@
+# SPDX-FileCopyrightText: 2025 Blender Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+# ./blender.bin --background --python tests/python/bl_pyapi_bmesh.py -- --verbose
+import bmesh
+import unittest
+
+
+class TestBMeshBasic(unittest.TestCase):
+
+    def test_create_uvsphere(self):
+        bm = bmesh.new()
+        bmesh.ops.create_uvsphere(
+            bm,
+            u_segments=8,
+            v_segments=5,
+            radius=1.0,
+        )
+
+        self.assertEqual(len(bm.verts), 34)
+        self.assertEqual(len(bm.edges), 72)
+        self.assertEqual(len(bm.faces), 40)
+
+        bm.free()
+
+
+if __name__ == "__main__":
+    import sys
+    sys.argv = [__file__] + (sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else [])
+    unittest.main()