Sorry but this change is terrible idea!! Im a blender iMac Pro user and for many years and this have completely broke my workflow in 2.92, its now just a complete struggle to even navigate in the viewport feels like a giraffe trying to walk for the first time.

So is there a way to re-enable it for MacOS, I assume there is a simple condition in the blender code that checks if its Mac or not, isn't it simple just for me to do a custom build with this check disabled so it attempts to use the GPU, Not to worried about potential bugs at this time

I have this black tile issue with denonising on GPU also. Im running an iMac Pro with the Radeon Pro Vega 64 16 GB graphics card, for me I have to turn off all the direct denoising to get an image looking like the expected render