I use @ember garnet's Mod Profiles mod, and I have one modpack with mods that I don't want to earn achievements with. I have another modpack that's solely QoL mods and adds no content whatsoever.
I want a mod I can add to the "vanilla" pack to cause it to override the "Achievements" setting to enabled in the mods menu. The inverse may also be useful for some people.
Alternatively it'd be helpful if WaffleDevs implemented per-profile configuration or configuration overrides. Then I could just add an override for my "Vanilla" mod profile to enable achievements.