Octane, Redshift, and eevee/Cycles all work on Metal, and Renderman and Mantra are CPU-only for now -- RM/Mantra have beta-versions that are GPU enabled, and Karma is nvidia-only and RM XPU doesn't work on macs at all yet, but I don't think many people are using either in production very much yet. I think the only GPU renderer people are using in production pipelines that's really locked to NVIDIA chips is Arnold, right?