I can't see this to be too difficult to code compared to Tabs, It would just be displaying a table of all the current settings I would of thought.
See it would just have a region list so you can double click on Bridge and it would play that so this would be like a Tab view, and as mentioned you can create the arrangement by choosing the sections and order to play/render. Maybe have a floating window option so as you select that section it will display it in the chord sheet view also.
But yeah try and get that smooth seek working for audio like you had with midi conductor, this will then also work for using Biab as live chord input .


https://www.soundonsound.com/techniques/power-arranging-reaper