I can't thank you enough for linking that!!!
It made me realize that there must have been a way to effectively downcast without getting NaN's. There's just no way that app could work on the devices it does with SDXL without having figured it out, so I scoured the web for references and dug in to figure it out. I'm happy to say I got it working on my M1 Pro! That also means memory usage is cut down by about a third, and speed is up by about 50% on Mac in general thanks to being able to work in half-precision instead of full.
I was able to do the same 512x512 20 steps in 17 seconds using a fine-tuned model (Realistic Vision 5.) SDXL took it's sweet time coming in at almost 3 minutes, so yeah probably not my usual workflow, but SDXL isn't even in my usual workflow on my 3090 Ti Windows/Ubuntu hybrid machine. I still use TensorRT and fine-tuned SD 1.5 models - 512x512 is roughly 3 seconds on that, but the beautiful part is when doing a 2000-iteration upscale and TensorRT caps out at ~30 it/s on Windows or ~40 it/s on Linux.
I have a little bit more testing to do for this, but I'm going to be releasing a 0.2.1 build in the next couple days. I would love it if you would give it another shot - I'll send you a message with a link, if that's okay with you!
With respect to AMD - that's a complicated answer, I'm trying to work with some AMD users to test out the combination of dependencies that will work for them. I'm not sure if anyone has managed to successfully use the GPU for AI on the steam deck, but I do know officially ROCm is unsupported and will be for the foreseeable future on the deck. I've seen people successfully use Stable Diffusion with CPU inference on it, which Enfugue will allow - but those same people reported it took half an hour to generate a single image on the deck, so I'm not sure it's worth trying.