They probably just intercept DLL calls, it's easy to do.
A driver hooking all executables (!!!) to then hijack loadlibrary, eh?
What could possibly go wrong, cough.
PS
I call bovine feces.
If FSR4 is a drop in .DLL, is there a technical reason AMD cannot enable it on any game that supports DLSS by replacing/hijacking the DLSS .DLL with their own FSR4 version?
If the inputs are compatible, it is doable more likely than not.
Ultimately, as with all TAA derivatives (RIP AI DLSS), you have motion vectors passed around.
Its a nice to have, and that is all it really is right now. People overvalue this shit waaay too much. Its a temporary thing.
It is overhyped, yes, but it is going nowhere.
If anything, we are going to get more of it.
I try to refrain from calling them fake frames and rather refer to them as interpolated frames although I still slip up from time to time.....
Bazinga frames.