Will I get banned if I install an unofficial version of FSR 4.0 in my gpu?

replacing dll will plain not work, javelin will prevent loading it (game will still launch but without that feature). the only way to do it is to replace file on a driver level - i dont have amd gpu, so i dont know how amd works. nvidia provides global override mode that allows driver to swap file on the fly without game interfering - and that doesnt get blocked by javelin

so tl;dr u wont get banned but unless amd allows for driver level version overrides like nvidia, it's impossible anyway