I wonder if you could use check-point and restore in userspace (https://criu.org/Main_Page) so that after the game boots and passes the checks on a valid system you can move it to an "invalid" system (where you have all the mods and all the tools to tamper with it).

I don't really care about games, but i do care about messing up people and companies that do such heinous crimes against humanity (kernel-level anti-cheat).

The war is lost. The most popular game that refuses to use kernel-level anti-cheat is Valve's Counter-Strike 2, so the community implemented it themselves (FaceIT) and requires it for the competitive scene.