Hi Rob:
I am in the same boat as you.
A few years ago someone showed me a program called WiseMix, but it didn’t seem to work that well…
I haven’t really checked it out since.
I have written on the Sony Vegas forums about HUI support and they claim that no one else wants it. If you would be so kind as to post this on their Vegas audio forums, maybe they’d start to listen…
Cheers,
C