The more I think about preferred workflow in BIAB, the more I realize that having more tracks in mixer (tracks on demand) will solve most of problems and requests related to RT's count, regenerations, bar freeze (bar-by-bar regen) and MIDI.

Regenerations could be done by simply copying the track to another mixer track freezing original and have the new one available for regeneration. So you can hear them side by side and/or together with whole arrangement. Create new track - repeat process for variation.

With track duplicate -> freeze you can achieve a highly requested "BAR FREEZE" option. You will just: "bar option"->mute what you do not want to hear. Or unfreeze->regenerate will (hopefully) give you new regeneration for these bars.

To get even more creative, have a "track folders" to keep mixer tracks organized by instrument.

P.S. This is not a workaround request or request to send me to RB, this is BIAB request smile