If you change your default sort method to Filename, does that speed it up? Sorting by filename is going to be faster than sorting by capture time.
Since we released our update that addressed the performance issues caused by Ventura, we haven't really seen any of the issues that people were reporting before we released that update. I assume you mean Monterey and not Mavericks, since Mavericks reached end of life before M1 Macs were ever released. While I don't anticipate that the latest build of Photo Mechanic on the latest build of Ventura is going to introduce any new issues, I can't guarantee that upgrading is going to fix your Ingest problem, because this wasn't a common complaint with Monterey to begin with. If you are wary about upgrading, I would recommend creating a volume on your boot drive to install Ventura on and test it out before upgrading your main OS.