The 'elephant' in the room is RealBand. It does every process mentioned in this thread. Begin your BIAB song project in RB to construct the song form and arrangement there. The user can complete the song and render it in RB or save the RB project as a BIAB native file, open that file in BIAB to quickly select, audition and render the completed and arranged tracks to export and complete in the users DAW of choice.

Here's the processes items I found in the previous remarks:

1. tabbed chord view. This is requested to so sections "correlates to its marker in daw multitrak software so the user knows where he/she always is in biab."
This is unnecessary in the RB because it is a DAW and that correlation exists in it as well as provides both the section view and the overall view.

2. the user can flip around easily in a song between song sections.
RB easily does this.

3. Section Text.
RB has this feature.

4. the other "problem" is biab chord sheet is "an up down affair". ive often wondered if instead it (chord view) should be organised like daw software.
RB has this DAW organized view in the Tracks View. RB also has multiple easily navigable views between Bars, Tracks, Chord Chart and Mixer.

5. biab doesnt think as in intros/verses/bridges/breaks/choruses/outtro sections.
RB thinks of song sections like every other DAW.

6. And it’s not just chords, everything can vary (at least slightly) from verse to verse, like the melody, lyrics, instrumentation etc. The best solution to that is a linear representation (one chorus) where you can customize any part because it gets its own bar number.
RB has both the linear representation and the BIAB format for Bar Numbers.

7. imagine a user with 2 monitors. on one is biab tabbed chord view. on second monitor is the users daw multitrak software with markers corresponding to the tabs in biab. now how bout this! user drags a tab from biab over to daw marker, et voila!biab intelligently drops its traks to the marker in the users daw only for that song section tab. traks magically appear. sorta like currently. the key aspect is to match biab markers and daw markers.
I don't have two monitors and I don't know if this is something possible. However, since RB has DAW Markers and sections can be selected, then such a transfer should work using RB sections. If the poster has two monitors, create a section in RB and test. This may already be possible.

8. let me also add that tabs wouldn't be fixed. they could be dragged around at the top of pipelines graphic if the user wishes to re arrange the song. they can be moved, copied, renamed. whatever. thus catering to any rearrangement of a users song. also each individual tab section can be played obviously on its own.
RB has this feature

9. Unfolding.
In RB, the tracks view is resizable and the Chord Chart is linear, one chorus and scrollable.

It's not my intent to endorse or disregard any of these processes. Some can be done in BIAB and some not but each can be done using RealBand. Starting a BIAB project in RB completely eliminates the need to create 10 or more individual BIAB projects and eliminates the need to generate and export multiple versions of instruments when RB can create and include every section's variation in a single track and single render.

BIAB Ultra Pak+ 2024:RB 2024, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.