That was a sticking point for us too. I didn't want to join them to the domain as our default policy broke a load of functionality with them so using SCCM was out the window. I eventually just moved all the NUCs and table units to a separate VLAN and gave them access to Windows update and the Windows Store (this one is important). I end up turning the access on and off to give us a little control on what updates are rolled out and when. By default the devices will check for updates and then reboot at 2am every day.
The Crestron firmware updates for the table units, AV ingest etc get applied via Windows update so there is no need to update their firmware separately.
Lastly we found that using a EDID emulator made them a little more stable. I believe that Crestron also have their own version now too (no need for a full on scaler).
Hope this helps!
We were having that issue when devices were left overnight. Turns out they weren't really hanging but the model of displays we used were the issue and Windows couldn't handle the constant disconnects from it. We put these in and that problem went away.