Quick pointer, because this is not something that happens that often but when it does is absolutely infuriating:
Not being able to enter quickly in turn-based mode because the currently-selected character is "currently incapacitated" (i.e. Stunned, prone, lethargic, whatever) is stupid as hell.
Entering turn-based is NOT supposed to be an in-world action the character itself does, it's just a function for the player to interact with the UI and the game. This restriction has no reason whatsoever to exist.