It would be great if we could add a Catalog item to the map as a query layer using an OOTB button.

That would be an efficient way to create a query layer; no need to fiddle with query layer setup. And it could be a good way to add an item to the map without locking it.
Pro already has all the information it needs to create a query layer; I know this because it automatically creates query layers for Catalog items that aren't registered with the geodatabase when an unregistered item is added to the map.
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