@jazzmammal
With respect,
I don't see 'complaints' .... rather, requests.
..... and I have to disagree with your assumption that 'The vast majority of users (90% maybe?)use one of the basic GM synths.' or 'there are some who really do use high end VST's with Biab but I think that number is pretty small.' More and more musicians are using good sample libraries simply because of the quality.
Band In A Box could be the ONLY solution for users of VST AND VSTi users, however 'high end'. This would make the software unbeatable in every respect. Maybe a wrapper could work. I suspect not though.