Thanks Andrew. I waited to get through some recent gigs, then upgraded to 10.3.2 as well. Like you, I found that BIAB ran ok. Phew!
I hope that PG Music will soon make sure to bring BIAB into compliance with the future iOS upgrade that it's not supposed to run on.
That would be an excellent time to make the fixes and improvements I have recommended in my wishlist posts for over a year.
Cheers! -Alastair