Is there a way to determine in a macro which UHK (v1 vs. v2) it is running on, and maybe even which firmware version?
Nope.
I was afraid you would say that
I have a few different UHKs, and I want to run the same configuration on all of them. However, the brightness of the UHK v2 LED display (white-ish) is brighter than the UHK v1 (red). So I would like to change some of my brightness macros depending on whether the macro is running on v1 or v2.
I’ll create a feature request issue (if there is none yet).