There is terrible shimmering on XeSS and FSR and I see this issue in all games, particularly those with foliage rendering FSR almost unusable in such titles. See below images. Intel just released XeSS 1.3 dll which has massively improved the shimmering and using this DLL in forbidden west massively reduces the shimmering to the point I found XeSS superior to FSR 2.2. Due to AMD's stupidity, they have made FSR non upgradable so even when they release FSR 3.1, its entirely up to Nixxes to implement it. Unlike XeSS and DLSS where we can mod in the new versions on Day 1.
Notice the shimmering and nosie on the moving foliage below? It was significantly worse than FSR on XeSS 1.2. XeSS 1.3 has cleaned it a lot and is superior to FSR 2.2. DLSS does not have this issue at all. Its entirely clean. In fact, if you set the render scale to 77% on DLSS using DLSS Tweaks, the image is superior to native TAA which also suffers from this issue.
XeSS 1.2
XeSS 1.3
XeSS 1.2
XeSS 1.3
XeSS 1.2
XeSS 1.3