With PMS 1.23.3, Plex have introduced a random sort order for libraries
With that option you can create a smart collection to your liking and make it available on the library recommended page or your Home Screen
Edit:
Apologies for getting overly enthusiastic. I had overlooked that we cannot publish smart collections to the home screen… that’s only possible for regular collections (which don’t have an option to be sorted randomly)
Therefore my post wasn’t particularly helpful for this specific feature suggestion
