Clearly RB is designed to be a linear, "tape" style DAW. So in a way its understandable that currently one might find it more productive to get a song arrangemet, together with tags, chorus repeat count, endings etc sorted out in BIAB first. And only then import this into RB and "expand" out the whole song into one long linear strip.

There are clearly two modes of operation here - one suited to a compact BIAB chord window with repeats etc,
and the other for tracking and final mixing and detailed editing of a now "frozen" BIAB arrangement.

In BIAB an arrangement might be 32 bars "on paper" with repeats etc. In RB this can become 100 or more bars
and if say we need to change a single chord - the first bar in the chorus. we would have to do this for each chorus that has been "printed out".

However it is quite cumbersome and not very time efficient workflow-wise, to have to go back to BIAB if one decides to make adjustmets to the initial arrangement, maybe just to change one chord, and then have to save it
and re-import it into the current RB SEQ project.

Far better would be - in a future version - to allow one to create and edit a BIAB arrangement wholly inside RB.

RB would have to also be able to store this BIAB chord arrangement INSIDE the RB SEQ file. This internal arrangement would then be used to generate the EXPANDED RB track version of the song.