RapidComposer, FLStudio and WinAmp just have a small vst that sends tempo,sync,play,stop,loop,continue from the DAW to sync them to it.
If you could just get a VST/VSTi in the DAW that it's sole purpose is to send the host's tempo,sync,play,stop,loop,continue to the main Biab app you could load the free reastream-standalone.dll VST Win or free AUNetSend/Receive Mac to send the Biab audio master or separate tracks and midi back to the DAW.
Here's a video showing Biab slave synced to the DAW with MultiRiffs generated in Biab playing along with the DAW tracks
Watch
Biab-Transport-VST-2.mp4Download
Biab-Transport-VST-2.mp4 A way of syncing Biab has been ask for many times
Why can't BIAB run just in slave midi clocked or MTC slave mode?
Asked for this already in ATARI days, and is still IMO a most desirable function.
There is a ReWireVST that works great with RealBand but not Biab
ReWire RealBand/PT and ReWire was suppose to be implemented in Biab but it never eventuated, maybe because of technical reason's ??
But you won't need proprietary ReWire, a small sync play VST should be easy to make as it only needs to send VstTimeInfo from the DAW to Biab's transport, this will then sync Biab with any DAW !