This is the workflow I use to produce best possible visual quality with Wan 2.2 T2V. Thanks to user The_Cook, I was able to adapt his upscale method for this workflow. It involves a low-res first pass and then a second upscaler pass.

Another bonus of this workflow is you get a quick low-res preview before committing to a lengthy generation so you can choose the best seed.

There are a lot of custom nodes in the workflow but they should be easy to install via ComfyUI Manager's "Install Missing Custom Nodes" feature.