Here at PikaOS we have written a nice helper wrapper script to ease NGX and DSR override settings for Proton's NVAPI. The code can be found here.
You need to be running a version of proton running this commit of dxvk-nvapi or newer.
The easiest way to ensure this is to use Proton Bleeding Edge directly from the beta branch of Proton Experimental in steam.
In steam launch options to override and update DLSS to DLSS 4 trasnformer model, latest ray reconstruction and the latest frame gen models prefix your game with nv_dlss_full.
nv_dlss_full %command%
If you are having trouble with the game not starting then it may not support the NGX updater, if that is the case prefix it with nv_dlss_override instead and manually copy the latest DLSS dlls from techpowerup into your game's bin directory.
nv_dlss_override %command%
Luckily you can easily check if it is working using the provided overlay, if it says override and preset K then you are good to go. You can turn this on using nv_hud_on and then off using nv_hud_off (this is a per game/prefix toggle).
nv_dlss_full nv_hud_on %command%
It will then look something like this (check the bottom corner):
In steam launch options to override and update DLSS to DLSS 4 trasnformer model, latest ray reconstruction and the latest frame gen models alongside 4x mfg prefix your game with nv_dlss_full_x4.
nv_dlss_full_4x %command%
If you are having trouble with the game not starting then it may not support the NGX updater, if that is the case prefix it with nv_dlss_override_4x instead and manually copy the latest DLSS dlls from techpowerup into your game's bin directory.
nv_dlss_override_4x %command%
You can use the same commands but 3x for 3x MFG.