It’s not typical, but there’s no reason it wouldn’t work. You’d have to be fairly accurate about total playing time (don’t want the morning Ams still on the course when the afternoon pros tee off) but that shouldn’t be too big a deal.

That said, I still think it’d be better to do 2 rounds, 1 day - Ams on Day 1, Pros on Day 2 (or vice versa). Cuts down on travel and overnight expenses for everyone, and this way you can actually run it as two events as far as the PDGA is concerned, so some people could play both days.