I see your point but I have to disagree. A highest point is definitely an important feature, but you're opening the door to include any important features inside the relations. This sort of data fits way better in wikidata statements, and imho, admin_centre is not a necessary role either, we just keep it around for convenience (like, administrative relations has a admin_centre since the start... yeah ok..).

Since most mappers use iD to edit, dealing with relations gets a lot harder for them, and there’s a good chance they might mess things up, especially when we’re talking about huge relations like islands or countries. That’s why I’d rather not overcomplicate things. The simpler, the better.

BR