Keychat's current MLS KeyPackage event is a replaceable event, which makes it easier to update and manage the KeyPackage. Events are replaceable, which means that for each combination of pubkey and kind, only the latest event must be stored by relays, and older versions may be discarded.
In addition, after a new member joins a group, an update commit is performed immediately.
Keychat can also publish the KeyPackage using NIP-EE’s kind: 443.
What do you think about using replaceable events to update and manage KeyPackages?