Cycles Apple Metal device feedback

Looks like this release:

blender-3.1.0-alpha+master.8c4edd1b379d-darwin.arm64-release

is quite broken. Most rendering tasks lock it up. Some, including enabling denoising on the one project I actually did get to load, cause it to crash the instant viewport denoising is turned on. The Rivet project linked above causes it to lock up in the middle of loading it.