If she syncs from the timeline, she can just delete the unwanted tracks before Autosyncing.
I’d save a duplicate of the sequence before doing that, so if you end up needing the ISOs you can still find them easily.
I don’t have experience with it, but Avid can do this with AS-11 export. This is the new file based delivery export function in MC7. The file compression used can be AVC Intra 100.
Avid can track different timecode rates during your edit. FCP does not have this function
Here’s an idea. Make a 12 minute NTSC sequence. Insert a black slug for the duration of the program. Put a timecode window burn filter on it and the export as a QuickTime movie.
You can now position this movie on a higher track over your future shows (crop the black so that you can see the underlying video.)