Is the ReWireVST suppose to be working now or is that just a bug that needs fixing to stop it working again ?
I just thought I'd try it as you have done a lot of fixing with VST support.
Can you try that with the BBMac21 in Beta.

https://www.dropbox.com/s/heftq3ymrs529bg/BB21-ReWireVST-Working.mp4?dl=0