The only point of no return I encountered was once you head into Baldur’s Gate itself, you can’t go back to any previous area. All the other areas before that may give you a vague warning implying you can’t go back, but you most certainly can. Though at some points, the only way back is to fast travel, since you can’t just turn around and go back the way you came because you had to jump/fall into a pit or something.
I do find that one point of no return silly. The only logical reason I can think of is that they didn’t make an uncursed version of the woods, so it would be immersion breaking to go back there. But plot wise? Shit doesn’t make sense at all. There’s no reason I shouldn’t be able to go back to Emerald Grove once I reach Rivington.