I've been saying this for years. You already made your song in BIAB right?
Use the command to save all tracks to individual .wav files. Open the folder and drag each file to your DAW. No need to use the BIAB VSTi. I can do this much faster.
I agree it is much faster to just use BIAB instead of this new VST. I had hoped the VST would be an improvement over what we already had but it appears to be literally one step forward (VST with multiriffs) and two steps back (very slow and missing lots of BIAB features)! And given that PG himself says everyone is happy with it including him, I guess they don't have any real plans to finish it.
Oh well, another year of "exciting new features" I won't use. Back to 32-bit BIAB and exporting WAVs.