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.

Looks to me like this is the case. Did some more searching and found only the same "Intel + Nvidia-GPU or AMD + Nvidia-GPU" formulation.