>>1732400>option to make it so it's locked by defaultLocking when you enter battle should be the default behavior as long as you are in "controller mode" before pressing start.
If you are using the mouse for the menus and then switching to controller, try settingskeyskeyboardAuto-hide cursor during battle.
That one works as long as you don't move the mouse after the auto lock triggers; if that's still annoying, try keyboardSelect control typeMouse Button Mode; it should always lock.
On CN they've added an option to prevent the cursor from ever showing in battle when it detects any controller input, so it's way less finicky.
And another option to stop asking for the controller type every time, hopefully coming soon to global.