https://wiki.openstreetmap.org/wiki/Relation:superroute
In my understanding of https://wiki.openstreetmap.org/wiki/Relation:superroute documentation and also https://wiki.openstreetmap.org/wiki/Superrelation for me superroute is a perfect fit for those relations. Also offers an easier QA as well as defined separation between the "sub-routes" and the full route.