I see in the knowledge base that my UR22 is compatible with Sierra. In the words of Sir Laurence Olivier when he was checking Dustin Hoffman’s teeth… “Is it safe”?
The Developers are still in the process of testing for Sierra. For the time being, I would suggest staying on 10.10 or 10.11 until we have an official announcement on 10.12 compatibility. I hope this information is helpful.
Many thanks-no rush 
Hi Chris, looking forward to some good news on this.