[Feature Request] Consider adding option to translate DLSS2/DLSS3 to FSR2/FSR3

Feature Request

I confirm:

• that I haven't found another request for this feature.
• that I have checked whether there are updates for my system available that
  contain this feature already.

Description

Recently, someone created a mod to map DLSS calls to FSR 2.0 calls for Cyberpunk.

See:

• https://www.reddit.com/r/Amd/comments/vk28fs/cyberpunk_2077_gets_fsr_20_via_mod_by_replacing/
• https://www.nexusmods.com/cyberpunk2077/mods/3001
• https://github.com/PotatoOfDoom/CyberFSR2

Quote from the mod creator:

This mod attempts to replace DLSS with FidelityFx Super Resolution 2.0. The mod is still in development, but early results are already quite impressive: My GTX 1080 is able to run Cyberpunk in 4k with about ~45 FPS which is a 2x improvement compared to the native 4k performance while having a very minor quality impact. Also, yes! this is mod is compatible with any AMD, Intel, and Nvidia GPU that can handle Cyberpunk.

How does this work?

Both FSR 2.0 and Nvidia DLSS are temporal upscalers and work (except for some minor differences) very similar. This means that both systems need similar data to work. Luckily, NVIDIA publishes its DLSS implementation as a dynamic library ( a dll file). This allows us to simply replace the DLL in question with our own version that is able to translate NVIDIA DLSS to FSR 2.0 commands. API reimplementations like Wine or DXVK work in a similar way.

Based on the previously mentioned info, this feature request is for you guys to evaluate if incorporating something similar to Proton in general, for games using DLSS, is something both possible and desirable.

Start by reviewing the linked CyberFSR2 project, its DLL replacement approach, and the cited mod reports. Determine whether a comparable DLSS-to-FSR2/FSR3 translation belongs in Proton and what compatibility constraints it would need to satisfy; completion criteria are not defined by the issue.