Sorry, I am not quite sure what that is. Sleep works great with my PC (motherboard is ASRock WRX80 Creator) and M1 MBP, but I can only adjust brightness through the OSD.
Personally, I rarely adjust brightness on my desktop displays and my ZMK keyboard volume buttons work reliably cross-platform.
I wish my personal was a mac as well, but I had to abandon macs when they abandoned me by not upgrading the mac pro for like a decade then kept me away by later ending support for eGPUs.