Thanks, Alex. Yeah, I know I can certainly buy a cheap supported card like that, and probably will buy a couple in the future anyway. For the moment, the cheapest method would be just to temporarily move my RX 580 to these other couple of systems for the quick firmware update. However, I like to have repeatable "solutions" in situations like this for future use, so I was interested in finding a way to bypass the Metal GPU test and still proceed w/ firmware updating. No biggie tho...just something I wanted to find a way to do, not something essential.