Pretty much what the title says. Probably make it a box players can tick upon creating a profile. "Include MCreator mods" or something, and players can turn it off.
Having been a part of the modding community for 10+ years, I can safely say that many people avoid MCreator mods, but its not often obvious when a mod actually is an MCreator mod, since many people dont mention it in their threads or in their mod's tags. There's a reason MCreator mods on Curseforge only get like 1% of the downloads of other similar mods that were done properly. Filtering out that stuff to not even show up in the first place would be nice, since many people don't want to accidently endorse MCreator by using mods made with it.
This would provide a simple solution for players to easily be able to avoid creations of one of the most hated parts of the modern modding scene. And players who enjoy MCreator can still download these mods by ticking the MCreator inclusion box.