“Being that the transcode will turn my current 30p into 24p”
that’s about the worst possible combo for a frame-rate conversion, as you have to drop one frame in every 6
there’s no neat way to do it, AFAIK
“All my XDCAM (EX) footage is being transcoded, one scene at a time into Prores (HQ). ”
you’re not doing this frame-tate conversion while you transcode your footage are you?
are you transcoding original footage or edited scenes?
your best bet would be to transcode your original footage, maintaining the original frame-rate
when your film is completed, do the frame-rate conversion through the best hardware you can get your hands on.
nick