While I already have a GPO that should in theory stop PCs from updating to Win11 is there anything I need to do in Desktop Central to also make sure that endpoints will not update to Win11 until we are ready to do so? 

Caveat: we are testing Win11 on a small group of PCs so we do want to patch and update IF they have been upgraded to Win11, we just don't want to push out any upgrades to automatically update to Win11.