If firmware update stuck, pair to PS5 and update there first

[[LUE] DarthEbola]

Admittedly obvious, and unfortunate for those without PS5 console, but if you get stuck on the controller firmware update and the controller turns off before the update completes, you can pair back on PS5 and update firmware there first, then rerun the setup process on PC.
I had to remove the controllers as bluetooth devices so that I could pair them again.
Going back and forth from PS5 and PC may require re-pairing the controllers in PC bluetooth and plugging in on PS5 to re-pair.