Most shaders don’t know how to handle sRGB either. They expect to be in linear-space, I think unless we clear up what is meant by sRGB there’s always going to be some confusion here.
I think what you’re calling sRGB is merely Rec 709 colorspace. Very few shaders are aware of the gamma curve that is going to be applied to the final output. It’s useful for luminance-based edge detection, which is why SMAA/FXAA likes it.
As for the rest of the stuff, any input/output in R8G8B8A8 UNORM can basically be treated as an alias for the swapchain format. Since that’s what 90% of games use, if you encounter a shader hard-coded to input/ouput that format, just replace it with R16G16B16A16 in HDR.
The only ill effect that would have in the case of ReShade would be double the required memory bandwidth (before colorbuffer compression).