Hi Strubbl, the old relation is still valid for the time from 2012-2023, so relating to historic info still relevant. I'm always careful of deleting tracks of other people. New relation is a lot more complex due to its exceptions and intersections (and therefore not completed yet). In the OSM wiki page also other obsoleted relations are linked. I'd apply the abandoned:boundary flag to it. These are the reasons not to change the existing relation.