If you're going to use SD Ultimate Upscale, I suggest leaving the positive and negative prompts blank and going for a low denoise. I also enable Tile/Blur ControlNet when doing this.
ty, I just started going down the SDXL rabbit hole but once I finish figuring that out I'll try upscaling.
I already have the extension, but not sure how my computer is gonna handle a 6x upscale 🥴