I think it's vitally important to be looking at the JUCE plugin as the way forward so your eggs are not all in the one Delphi basket.
The Plugin seems to have developed faster with things being added overnight on both Win Mac easier than it seems to happen with the Biab main. The PLUGIN seems to always have to wait on things to get done in BBW4 because the BB programmers are working on the Mac or Win BBW, meanwhile Adar is still waiting, he may as well being doing the whole programming that he is very good at rather than waiting on Delphi programmers. If I as someone with no programming training can do it in Reaper surely Adar C++ programmer can handle this in the PLUGIN.
Let the development run parallel transferring the generate code directly in the PLUGIN gradually, there was word from the beta forum that is wasn't going to happen, I think this will be a mistake if true.
If I can generate up RealDrums, UsersTracks and Loops in Reaper surely you can add this code for a start to the PLUGIN ?
I have been looking into this long enough and see it could be done, I would much rather see PG go this way rather than me having to develop a 3rd party Plugin to do this or see other companies do this. I know many thing I have suggested here to PG to do have been implemented by other companies after the fact like sample sets for VST's like Session Guitars and UJAM Guitars, RealTracks Live Arranger.
All the bloat you have in Biab you don't need in the PLUGIN as most can be done in the user's DAW.
If users want all the functions in Biab they can use it then simply SAVE FROZEN SGU and open in the PLUGIN and have the identical thing in their DAW instantly. At the end of the day all the PLUGIN needs is the wav instructions.
Get rid of all the old limitations like time signatures and 255 bar limit.

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