You can use DRUMSOLJ.STY and Force Midi Drums, you can generate up a midi drum solo track in another instance of Biab with PlayableRealDrums enabled, play through to find the riffs or rolls you like then just highlight those bars on the Chord Sheet, now drag the Drum track at the top of BB to the MID Drop, when green drag and drop into the other instance of Biab choose the track and position and check "Merge with existing data".
You can import any section from any midi file drums you may have.
You can also use a VST like EZDrummer, just drag export the midi solos from Biab DRUMSOLJ.STY into EZDrummer users library.
You can change the Sforzando VST in the PayableRealDrums track to EZDrummer and it will play the midi drums in the EZDrummer track where you have the green mute sections in the BB Piano Roll, if you want the same sample set as Sforzando then you need to use ElementVST to chain Sforzando with the same sample set it was using after EZDrummer and set EZDrummer to just send it's midi out to Sforzando.
As we still can't chain VSTi in Biab VST Handling Fixes Needed

See EZKeys EZBass EZDrummer Jamstix Playable RealTracks

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