I just did a weird thing with gift wraps in Keydex and I want to make sure it's not dumb. I'm having a bug where lockboxes are showing back up on the devices of key holders after they have been removed. Like this:

1. Alice invites Bob to be a key holder for their lockbox

2. Bob accepts

3. Alice publishes a shard of the lockbox data for Bob to download, gift wrapped and addressed to Bob.

4. Bob changes their mind and deletes the lockbox from their device.

5. Later when Bob reopens the app it downloads the shard event again and recreates the lockbox.

Of course I could maintain some local state about what has been deleted, but it would be better to just nuke the shard from the relay. We could ask the original publisher to do it, but we can't guarantee they are online. So what if we just include the ephemeral key used to gift wrap the shard in the seal? Now Bob can publish a NIP-09 deletion request to delete the shard.

I could see this being useful in other places too. For instance you could have a type of direct message that gets deleted from relays as soon as it is downloaded by the recipient.