I previously have used Vegas Pro versions 15 and 19 and there are multiple render options including (among many others) MainConcept MPEG-1, Sony AVC/MVC, and many more render formats including 720p and 1080p.
Considering upgrading to version 23 and installed and there are only options for AVC (H.264) at 720p.
I've checked the show all formats checkbox, but that doesn't show anything more.
Is there an additional options install that the regular installer does not run that I need to download and install?