Is it possible to set custom DLSS preset above 1.0 resolution scale? (Supersampling)

[TatsunaKyo]

This might seem a weird question, but I've already seen this before: it is mentioned both in NVIDIA's own DLSS Programming Guide and it has been already reproduced my modders like PureDark: in his GTA V and Skyrim mods, you can use DLSS to target an higher resolution (for example 1440p) than your monitor's (for example 1080p) while also upscaling from a lower resolution (for example 720p).

You might suggest that one could use DLDSR to replicate the same effect, but DLDSR is plagued with issues on my system and I've been getting tired of having to put up with it. Whether the game(s) force(s) me to change my resolution altogether, messing with my icons and readability, or the sharpness and image artifacts DLDSR often produces, I'm honestly sick of it. It interferes with G-SYNC and Frame Generation too. I'd rather both the upscaling and downscaling process be done by the GPU (DLSS) or with a combination of upscaling done by the GPU and downscaling by the monitor. Might this be possible to implement? Or just like modders you need to do it at a per game basis?

And if this is not possible, I read that Optiscaler can also change the Output Scaling of DX11 and 12 games: would it produce approximately the same results? Perhaps by providing supersampling to a game and then using DLSS? Or is it something else entirely? If that is possible, can a little guide be posted how to go about it?