I don't know how fast Parallels is these days but it might be a way to solve compatibility issues that seem to keep popping up.
The main Biab Win app should run fine, with the Win BBPlugin you might be able to set the generated SavedTracks folder and save it with SGU to a shared folder this might then load into the Mac BBPlugin if the Plugin it's self has no compatibility issues (not bbw4 app that gens up the tracks) ?
You could batch convert any Mac RT RD to wav as Mac will read wav but Win won't read aiff/m4a. You will need to convert the m4a demos to wma also.
The other issue was the Library in RealTracks & RealTracks/Direct Input folders Mac calls it LibraryM (as Library would not work) so you need to create a symbolic link for Library to LibraryM.

Further.. running the Win exe on Mac will allow you to inject the tracks in Win Biab directly into Mac Reaper as Win Biab will save a temp.txt file of the selected mixer track, this text file can be opened by Mac Reaper and you will get the track instantly.
In Parallels Mac can access the Win folders so Mac Reaper would just read the txt file from the bb Win folder and get instant tracks/track sections.
The tracks are in the originally used sections so this gives full non destructive editing control of what you want.
If Reaper's not your DAW AATranslator will translate a Reaper project file into other DAW formats.




If they add the BBoutput.txt to Biab this will give all the current track data that can be read directly into Reaper.
It they add this to the Win version then hopefully Mac should get it also.
This is what the BBoutput.txt will give: