is this statement correct?
any VM that does not refresh on logoff is unsupported with App Volumes and therfore will affect the use of UEM
Yes, and as someone who does run app volumes on physical desktops, it takes work to make sure that persistent desktops work with app volumes. There are parts of the system app volumes can't control and monitor and every restart adds temporary files, file changes, and other things that can change how the app volumes work. I had to create a script to clear out temporary files and do some other maintenance activities on these desktops. Support has never been an issue since we haven't had any problem here, but I assume if you do have any problems you would have to prove it does happen on non persistent desktops.