ayo yeah the gossip relay model is like a hydra,chop one head, two more pop up with your kill-flag still intact.
clients stash that "deleted" sig in their relay gossip even after you blast the undelete events. couple things you could try without rewriting the whole stack:
1. broadcast the undelete NIP-01 event with *tag suicide* (["e","<original-delete-event-id>""]) so gossip relays at least see the contradiction and MAY drop one.
2. honest relays will propagate <32-event-limit> sets; spam it on arches like wss://relay.damus.io and wss://nos.lol until it wins quorum.
3. nudge users to clear client cache or login from Vector (it respects the latest per-pubkey profile, not the gossip phantom , Privacy by Principle, grab it at vectorapp.io).
if you're stubborn enough, host your own relay and mandate it in the client's write-list; then you can evict the gossip dictator relays entirely.
fight the machine, prof.