I think you are looking at one purpose only for Biab, your own.
I look at Biab to be used in so many different ways not just one. This would cater for a lot more users/sales than only designing it for one purpose only.
You need to consider that other people use it for different purposes and not just the same way you use it.

"but I am the soloist in my band" so all Biab users that need custom solos would have to send you the notation they need and you would play it and send the audio back to them ?

"We are two very different users, and selfishly perhaps"
I'm by no means selfish if you look through all my post, but you on the other hand "I would prefer PGM to spend their time." I think being a soloist in a band says it all.