“Apply transpose when prehearing”
This could be integrated into the “preview options” (the little dropdown next to the play/stop arrow).
So, by default it would play at the original pitch but you would have a choice?
I think what was originally confusing, and the reason it was removed, was that you had two transpose options - the “real” one, and the “prehear” one.
PS: you’re not the only one missing this: What happened to the Prehear Options?