I too am working on this and have found that the 0 command does not work. I have added in an additional command to uninstall the screenconnect app from the system via a shell as admin with "wmic product where name="ScreenConnect Client (xxxxxxxxxxxxxxxx)" call uninstall /nointeractive" on it to make sure the software is removed from the bad install.
What I have found is if I manually run disable then uninstall via the software tab then enable everything works I just want a way to script this as well. It would be very nice to have.
I also found that the best way to have the agent to just disable was to do an SQL update as the command 0 was not running on systems that had duplicate screenconnect GUID's.