Okay, so you are trying to create a writable volume but then as an appsatck.
For me this is a big nogo. You use appstacks for application settings, the fact that HKCU and c:\Users is excluded is for a reason, do not use it. I believe you can;t even use it the way you would like to do.
Either use writables for this of use UEM to capture these settings. If you have Appvolumes licenses I believe you also have the UEM licenses and it is way more easy to use UEM for this...