Hooking into game's backbuffer

This is probably a dumb question, so here we go: Would it be possible to modify the way reshade computes it's effects to instead of creating it's own backbuffer that it later overlays on top of the game, inject/override the game's internal backbuffer? (which would require modification on a per-game basis)
Understanding that overriding the game's internal backbuffer could have some SERIOUS negative effects, would it be possible to perhaps hook into that backbuffer and copy-paste the information that the game's backbuffer outputs? (possibly before or after tonemapping, which again, would require modification on a per-game basis) The reason I ask is because in doing this, we could possibly create render flags (for ex. tell ambient occlusion to not render behind particle effects, or get HDR data.) Or am I mistaking how we would go about doing that completely?

Also, I am well aware that Reshade was built to be universally compatible with practically all games, unlike ENB Series, and I want it to stay that way. However, I would also like to have an open-source alternative to ENB Series, and wondered if this would even be possible, and how much effort it would take to do so.

P.S to Borris: Where be that source, yo?

Please and thank you,
NoMansReshade.

This is exactly what ReShade does. It replaces the games depth and backbuffers. No, you cannot magically get HDR this way. Games already compress the color range in their own shaders.

Thank you for such a quick answer!

My understanding is that ENB is an injector, because of this, could we theoretically do it the "Hacky" way and just intercept the runtime shader buffers and modify parameters, such as modifying the color of the sky? Because my understanding is that some games give lots of access to foreign binaries when named correctly. I am only asking before I waste large amounts of time trying to do this

Also, correct me if I'm wrong; But it will probably be super duper complicated to do this. Keep in mind that I have a reverse engineering background.

Please and thank you,
NoMansReshade.

You can do anything. But ReShade was written to work everywhere, so it doesn't and cannot do everything.

Fair enough. Thank you so much for your answers!