VR UMG Compatibility Plugin!

I’m not sure what your issue is, what do you mean by 7 errors? And just to get this straight you downloaded the plugin from the ? then the example project?
The link you should use for 4.12 is this one:
https://VRUMGPlugin/files/405288/VRUMGPlugin4.12.V0.3.zip
As its already been compiled so you should’t have to rebuild it

As for the changing controllers I’m not sure, UE4 doesn’t re-poll the controller hands from steam VR during game play so steam VR can switch the hands but UE4 doesn’t know, that might be it