Okay, I'd say that `highest_point` is a little different than other "important features" because it's fundamental to the physical 3D shape of feature, bounding the feature by the z axis while the multipolygon ways bound it by the x and y axes.

But yeah, personally I think it's okay to use mapping patterns that are convenient but not strictly necessary (as long as they are accurate and useful). In this case I tried to lay out why it's indeed necessary to mark the highest point explicitly in order for an app to know this value. Wikidata is great but it's not a replacement for OSM.

I don't really see iD's relation handling to be an issue here since I haven't heard of any problems like this with `admin_centre`.

If you're a local mapper then by all means, feel free to remove the memberships if you want until this can have a broader discussion. But please retain the values in the US since the local community here doesn't seem to have an issue with the pattern.