The trick is
A. set the target track to MONO
B. set the L&R option for MONO tracks mentioned above
C. select however many inputs you want to record

Then RB does what (to me) is intuitive; it records each track on a MONO track. If you enable 8 inputs on your interface, as we often do, it will record 8 MONO tracks.
So you can have a L/R piano on 2 tracks, and a bass on one track, and vocal, harmonica, sax or whatever on other individual tracks.

Most DAWs do this, RB just does it a little differently.
Pick a target track as MONO, and it handles the rest and creates 8 individual MONO tracks .. and is smart enough to use the next available blank track, so it doesn't overwrite any tracks that may have been in the 'next 8 tracks' if they have data.

I do not work here, but the benefits are still awesome
Make your sound your own!