Please read again lol
They have an optional pass with upscaling over it.
“ Contrast Adaptive Sharpening (CAS) is a low overhead adaptive sharpening algorithm with optional up-sampling. The technique is developed by Timothy Lottes (creator of FXAA) and was created to provide natural sharpness without artifacts.”
Contrast Adaptive Sharpening (CAS). Contribute to GPUOpen-Effects/FidelityFX-CAS development by creating an account on GitHub.
github.com
“ You can use the q, w and e keys to set different CAS modes. q sets it to no CAS, w sets it to up-sampling, and e sets it to sharpen only.”
CAS is to sharpen but you have the option to sharpen and after upscale.
AMD is not dumb to use the terms wrongly.
Edit - The fact your example was that “upscaling” word in the FidelityFX CAS (a Sharpen algorithm) means you really dig deep in Google and just find that reference... the hard work you did tells you more than you think.