Auval and Auvaltool not working through SSH
This is a long shot, but I once had to install tmux with brew install tmux (and I already had https://brew.sh set up and ready to run) so that I could graphically log in and establish a terminal session for the user in question. 

With fast user switching, you can then return to the log in screen - leaving that one user console session blessed with full GPU and full graphical console permissions and then ssh in to attach to the existing TMUX sessions.

Hopefully someone has a more direct answer, but after several days of bounties and some great comments trying to back into the answer, I wanted to get on the record that a graphical log in does have higher powers and permissions and you just might need that for now if no-one has a better fix for this.