To be honest, I think NVIDIA Optimus iGPU+dGPU is just the most common configuration by a huge margin so you hardly hear about other multi GPU configs. However looking at the repo https://gitlab.freedesktop.org/hadess/switcheroo-control it doesn't have language specific to NVIDIA that I can see. And, if openSUSE is now advertising it as their preferred way of managing multi-GPU configs, I'd imagine there is the possibility of improving it if there is missing functionality.