I added the function to mount or dismount a unit by pressing the Y button while the cursor is on the unit in the item arrangement screen during preparation.
I had long considered this feature to be necessary, but when I had tried to implement it before, it had been technically difficult, so I had changed the mount/dismount specification as a workaround. This time, after receiving a request, I tried again and found it surprisingly easy to implement. This is because my understanding of the game's mechanics has improved.
However, it's not without issues. Initially, I intended to add this function to the unit selection screen. But pressing the Y button simultaneously with the L/R buttons caused conflicts with auto-unit selection, resulting in bugs, which is why I moved it to the item arrangement screen. In these circumstances, please do not point out the lack of consistency in not being able to mount or dismount on the unit selection screen.
