It's 6 months spent on Win and 6 months spent on Mac, it only needs a few tweaks for the Win version to work well under Wine.
Since I bought Biab/RB it has complicated my life no end, but I do it as it had to be done and I didn't give up on it, the result this year has been a massive leap with many things that I spent so much of my own time working out and making demo examples how it could be implemented in Biab/BB VST to lift it to a higher level. I'm sure all here have benefitted by all these improvements.
There were users complaining about all the Reaper info I posted and others saying "just ignore all that crap", "it can't be made better because of old users with old computers", there was about zero support or interest when I posted all the info, but now users don't mind using the new features that this has now given Biab/BB VST.