I think a single light keystroke(without having to hold it down for seconds) is more user friendly for ending turns. Also there must be a warning and confirmation when a player tries to end their turn when they've made no move at all.
I have added a setting where player can configure the end turn delay to be up to x4 faster. There is also a prompt to confirm if player did not spend any AP during their turn.
I think a single light keystroke(without having to hold it down for seconds) is more user friendly for ending turns. Also there must be a warning and confirmation when a player tries to end their turn when they've made no move at all.