Blog talk:Adnoam/Updates to Template:Item/@comment-36504000-20200821125852/@comment-36504000-20200821155156
If the ItemList does not contain the information, could the template/module add a link to it, similar to how you're directed to create category pages if they don't exist? That way you'd be directing those editors who don't know the module to it (and providing those who do with a handy link and reminder). That could also have the additional benefit of avoiding those manual category additions people often do, since it'd be less likely to have pages lacking ItemList data. Admittedly it is a bit higher barrier to entry than just adding to the template, but not too much higher imo.
As for what to do with the already existing pages, I've seen that in the past a bot has been used for this, but I don't know if any current editor is familiar with how to do that. I agree that if it is to be implemented automatically then it would be best to entirely remove the EffectX fields from the template, to avoid either conflicting information or fields being ignored.