Will have to see what December brings, for the Win version anyway, to see if there is any direct play, instant generate or Live Arranger mode for the main Biab app or the BBPlugin/Standalone. The easiest way for it to work direct on Mac is if PG added a menu item to save the track data to a txt file that will load directly into Reaper.

If the BBPlugin/Standalone is improved to have all the generate/play direct from the source files functions self contained within it then there's no reason why it could not be released on Mac at the same time as Win Dec 1st, this would also allow it to work on Linux using a PCvst bridge.

If not, the way you could run the Biab Track Injector for Reaper on Mac would be to freeze the tracks in BB Mac and save the SGU then open that SGU in a BB Win app only running under Wine. This will give the track data text file that Reaper will read and insert into a track. You would not have to click Gen/Play in the BB Win as it will just give the track data saved in the SGU without the need for the RTs RDs as these would be loaded into Reaper directly from the Mac RTs RDs source files.

https://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=716019

https://stash.reaper.fm/u/ReaTrak (Scripts for Biab Reaper)
Open SGU in Reaper Instantly