have you ever tried running rb in linux ?
I've just tried it a bit, but I don't normally use RealBand, so don't know what I'm doing.
Two early observations, though:
1) It seems to find only two of the DXi/VSTi synths I have ... CoyoteWT and Kontakt. BiaB finds also Reaktor 6, sforzando, VSTSynthFont64 and EZdrummer. (Neither find the Linux-native VSTs, which I guess is unsurprising. Linux-native Reaper finds them all, of course)
2) At a first try, I have a style apparently playing, but I get no readings on the master volume level meters and no sound. That may well be just because I don't know what I'm doing, or it may be indicative of a problem.
FYI, looking through the VST instruments that Reaper finds, I see both VST2 and VST3 versions of Scaler 2, which is a Windows VSTi that neither BiaB nor RB found, so there's something fishy about their VST handling. If find EZBass and EZKeys, but both are expired trials, so perhaps BiaB/RB not showing them is smart.
I may try to explore things more later.