What I’m trying to say is that type=superroute makes little difference compared to nested type=routes. The only data consumer I know of that actively consumes nested relations is Waymarked Trails, which equates type=route superrelations with type=superroute relations. For example, it lists child relations under this type=route superrelation just as it would list one tagged type=superroute. Apart from that, you could consider Wikidata to be another data consumer, but its OpenStreetMap relation ID (P402) property couldn’t care less whether the relation is tagged type=superroute, type=superduperroute, or type=überloopdelooperroute.