I did NOT recommend to retag https://www.openstreetmap.org/way/1427690967 from racecourse (sports_centre + horse_racing) to equestrian center (leisure=horse_riding). Here the object (area) representing Porto Santo Equestrian Center is https://www.openstreetmap.org/way/1282997073, and now you have produced another smaller equestrian center inside of Porto Santo Equestrian Center, which does not make much sense to me. Horse riding arenas should be tagged with leisure=pitch + sport=equestrian.