I have been using multiple endings since they first were introduced back in 2004 (I think).
There are some quirks, I agree, but in general they work just fine. I do use the unfolded methodology - I am not even sure they can work with the BIAB chorus repeats, since you need to know, by actual bar number, where the endings start and end.


BIAB for Windows Version 2019 (643)
Windows 10 (1909)