I recall reading somewhere that BIAB now allows a user to edit individual drum stems. Is that true?

I've been looking over the app, and I really cannot see where this function is.

Some of the RealDrums include stems. As of version 2024, there are about 150 full RealDrums styles that have stems (not including RD variations of those). If you are in the MultiPicker - RealDrums tab, click the Settings button and select 'Show stems'.

Now you can choose any one of the RD's that are displayed. For example 'ModernPopBallad16ths^'. Underneath the RD list there are checkboxes for which of the stems to show. Select them and press Generate. The regular Drums track will have the mix like it normally does, and the individual stems are generated on Audio / Utility tracks. You can adjust the volume/panning/reverb of individual stems, export the tracks to a DAW, etc. Note that these are recordings from the individual drum mics, they aren't fully isolated tracks, except in some specific cases e.g. percussion parts.

When the drums are MIDI drums they can be edited in the piano roll the same as any other MIDI track.

Don't forget to freeze the track after editing.

If you have Reaper you can edit the stereo drum track to how you like then instantly convert it into Stems (if available).

Thanks