Some mods target the Mono version of the game, which is available by opting into the Steam beta branch "alternate"

SwapperPlugin
Allows seamless swapping between the il2cpp and mono backends. Can be used to install the mono and Il2Cpp version of a mod seamlessly
By the_croods
CHANGELOG
1.2.1
will actually disable mods that have mono and il2cpp in their name now.
1.2.0
Fixed bug where il2cpp mods weren't detected properly. Changed it so that if any s1api is detected it gets skipped
1.1.0
Added support for the S1API, which im considering another backend. Go check it out! Its super helpful!
1.0.0
Initial release