Reaper will save the Biab VST current state.
If you save to SGU, maybe best to save it in the Reaper project folder.
You are in the Mac OS X forum.
Here is a response to your post in the Win forum
https://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=557419#Post557419
make sure you have email notification set ON so you will be notified when someone responds to a post.