Left Alt + Left Shift keyboard layout switching behaves inconsistently

[unxed]

1. Configuration limitation (Wayland)
   It is currently impossible to set the combination as "Alt + Shift" in the settings. The system only allows setting the reverse order: "Shift + Alt".
   This requires a reversed press order (see below), which is inconvenient.

2. Strict key press/release order requirement (both X11 and Wayland)
   Previous behavior: The specific order of pressing or releasing keys did not matter, as long as there was a moment when both keys were pressed simultaneously. For example, the sequence [Alt down -> Shift down -> Alt up -> Shift up] worked correctly.
   Current behavior: The system requires a strict sequence. Currently, it requires [Alt down -> Shift down -> Shift up -> Alt up]. Not very comfortable. Actually, it is severe pain.

Also, some observations (both X11 and Wayland):

1. When "Shift + Alt" is set, the system registers/displays it as "Shift + Meta", not "Shift + Alt".
2. The panel adds the letter L or R to indicate which modifier is being used, but only to the second key in combination. First modifier is saved without L or R postfix.

Possible duplicate: #13361