I prefer to do this in RB because you've got 48 tracks to mess with. I will select as many different soloist RT's as I want and let them generate the whole song. To be clear, RB will only generate one active track at a time as long as you uncheck the box that says "generate whole song". This is a trick part of RB, it can act as another version of Biab if you want but I never do that. It's a DAW, make it act like a DAW. If you want it to act like Biab then go back to Biab in the first place. Anyway, in that mode you work with one track at a time just like any recorder.

I did one months ago with something like 10 soloist tracks. Then I started chopping them up by deleting bars I didn't like and leaving bars I do like. Then use mute/unmute the tracks while the song is playing and gradually narrow down which parts of those 10 tracks I wanted to keep. After that I consolidated those pieces of 10 tracks down to one track for the final mix.

Believe me, this is way, way easier than trying to use F5 and other stuff in Biab. RB lets you use up all 48 tracks if you like to experiment. One cool trick with RB is you can change the chord grid and generate more tracks in the same song just for fun without changing any tracks you already have. You can change the chords AND change the style just to generate more tracks. Making some appropriate chord subs can completely change what a soloist generates. With the thousands of RT's now available plus thousands of midi styles available the possibilities are endless. I've also mixed in midi soloists with RT soloists because I have SampleTank 3 and I can get real close with the sound of a sax or guitar or piano solo to the sound of an RT solo using the same instruments. You can't begin to scratch the surface of all that in Biab alone.

Bob

Biab/RB latest build, Win 11 Pro, Ryzen 5 5600 G, 512 Gig SSD, 16 Gigs Ram, Steinberg UR22 MkII, Roland Sonic Cell, Kurzweil PC3, Hammond SK1, Korg PA3XPro, Garritan JABB, Hypercanvas, Sampletank 3, more.