diff --git a/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features/odk_layer.c b/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features/odk_layer.c
index 914d7fe7..5c430461 100644
--- a/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features/odk_layer.c
+++ b/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features/odk_layer.c
@@ -45,7 +45,6 @@ bool process_odk_layer(uint16_t keycode, keyrecord_t *record) {
                 case OU_GRV:
                 case KC_SPC:    // When space is added by Clever Keys
                 case CNL_ODK:
-                case PG_ODK:
                     return true;
         
                 default:
diff --git a/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features/os4a.c b/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features/os4a.c
index 671ca35a..a64e8f40 100644
--- a/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features/os4a.c
+++ b/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features/os4a.c
@@ -57,10 +57,12 @@ bool process_os4a_keys(uint16_t keycode, keyrecord_t *record) {
     return true;
 }
 
-bool process_os4a_layers(uint16_t keycode, keyrecord_t *record) {
+bool os4a_layer_process_outcome(uint16_t keycode, keyrecord_t *record) {
 
-    // Should keycode exit the OS4A layer ?
-    if (os4a_layer_changer(keycode)) { return true; }
+      // Should keycode exit the OS4A layer without further process ?
+    if (should_exit_os4a_layer(keycode)) { return true; }
+
+      // Should keycode stay on the OS4A layer, e.g. Callum mod ? 
     if (is_oneshot_ignored_key(keycode)) { return false; }
 
     // Add OS Shift when no other mods are active.
@@ -81,7 +83,7 @@ void mouse_mods_key_up(uint16_t keycode, keyrecord_t *record) {
     //if (get_mods() & QK_ONE_SHOT_MOD_GET_MODS(keycode)) { 
 
     // When ctrl or shift are released after being held, exit the OS4A layer.
-    if (!record->event.pressed && !record->tap.count) {
+    if (!record->tap.count) {
       os4a_layer_off(os4a_layer);
     }
 }
@@ -99,13 +101,15 @@ bool process_mods(uint16_t keycode, keyrecord_t *record) {
   if (IS_OS4A_KEY(keycode)) { return process_os4a_keys(keycode, record); }
 
   // Behaviour of the OS4A layers
-  if (record->event.pressed) {
-    if (os4a_layer != 0) { exit_os4a_layer = process_os4a_layers(keycode, record); }
-
-  } else {
-    // When Ctrl or Shift are released, for mouse use.
-    //if (mods_for_mouse(keycode)) { mouse_mods_key_up(keycode, record); }
-    if (os4a_layer != 0 && exit_os4a_layer) { os4a_layer_off(os4a_layer); }
+  if (os4a_layer != 0) {
+    
+    if (record->event.pressed) {
+        exit_os4a_layer = os4a_layer_process_outcome(keycode, record);
+    } else {
+      // When Ctrl or Shift are released, for mouse use.
+      //if (mods_for_mouse(keycode)) { mouse_mods_key_up(keycode, record); }
+      if (exit_os4a_layer) { os4a_layer_off(os4a_layer); }
+    }
   }
   return true;
 }
diff --git a/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features/os4a.h b/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features/os4a.h
index 0281eca0..ab2324a9 100644
--- a/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features/os4a.h
+++ b/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features/os4a.h
@@ -25,8 +25,6 @@ extern "C" {
 #endif
 
 extern uint8_t os4a_layer;
-//extern bool exit_os4a_layer;
-//extern bool pending_OSL;
 
 void os4a_layer_off(uint8_t layer);
 void os4a_layer_on(uint8_t layer);
@@ -37,7 +35,7 @@ bool process_os4a_keys(uint16_t keycode, keyrecord_t *record);
 
 void update_osl(uint16_t keycode);
 
-bool process_os4a_layers(uint16_t keycode, keyrecord_t *record);
+bool os4a_layer_process_outcome(uint16_t keycode, keyrecord_t *record);
 
 void mouse_mods_key_up(uint16_t keycode, keyrecord_t *record);
 
diff --git a/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features_conf.c b/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features_conf.c
index e8f6b9f1..a3f43425 100644
--- a/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features_conf.c
+++ b/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features_conf.c
@@ -202,7 +202,7 @@ uint8_t get_os4a_layer(uint16_t keycode) {
   }
 }
 
-bool os4a_layer_changer(uint16_t keycode) {
+bool should_exit_os4a_layer(uint16_t keycode) {
   switch (keycode) {
     case OS_FA:
     case NUMWORD:
@@ -247,7 +247,6 @@ bool is_oneshot_cancel_key(uint16_t keycode) {
 bool is_oneshot_ignored_key(uint16_t keycode) {
 
   const uint8_t mods = get_mods() | get_weak_mods() | get_oneshot_mods();
-  //if (keycode == OS_ODK && (mods & ~(MOD_MASK_SHIFT | MOD_BIT(KC_ALGR)))) { return true; }
   //if (keycode == OS_ODK && (mods & ~MOD_BIT(KC_ALGR))) { return true; }
 
   switch (keycode) {
@@ -266,12 +265,11 @@ bool is_oneshot_ignored_key(uint16_t keycode) {
     case OS_RALT:
     case OS_LALT:
     case OS_WIN:
+    // OS_FA must be on the list, to be combined with Alt
     case OS_FA:
     case NUMWORD:
     case TG_FA:
       return true;
-/*     default:
-      return false; */
   }
   return false;
 }
diff --git a/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features_conf.h b/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features_conf.h
index ad8327eb..62c06708 100644
--- a/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features_conf.h
+++ b/keyboards/splitkb/kyria/rev1/base/keymaps/Kawamashi/features_conf.h
@@ -30,6 +30,6 @@ bool process_custom_tap_hold(uint16_t keycode, keyrecord_t *record);
 uint16_t get_ongoing_keycode_user(uint16_t keycode);
 
 uint8_t get_os4a_layer(uint16_t keycode);
-bool os4a_layer_changer(uint16_t keycode);
+bool should_exit_os4a_layer(uint16_t keycode);
 bool to_be_shifted(uint16_t keycode, keyrecord_t *record);
 //bool mods_for_mouse(uint16_t keycode);
\ No newline at end of file