The problem is with relays not accepting those “delete” requests, hence this could totally be possible if you only write to paid relays which accept your “delete” requests, this could also not work if you write to a relay like the nos.lol one which broadcasts the notes to a large number of other relays.. honestly I’m not the most knowledgeable on this so please don’t quote me I’m taking an educated guess lol anybody reading this with more information please step in and correct me if I’m wrong 😄