Is there a generated media plugin for Vegas that would generate a simple time / frame counter on the video, and could be set to count both up and down?
Ah, found a partial solution. I didn't realize the Sony Timecode was a Video FX, not Generated Media. This was enough for my current purposes, but any tips about what I described are still appreciated. :)
(a simple solution is to render a video from some other program and insert that to the project)