Ashen Key lockboxes had the potential to be a great addition to the game but were not allowed to reach their full potential as the keys were not made more widely available in the World.
Ashen Keys could be a great inducement to stay on one server and reward those that stay on one server - assuming diving is not going to be removed.

Add Ashen Keys to each World Event and an Ashen Keys to Shipwrecks.
Add a mechanic so you can merge keys into a key ring so can carry multiple keys in the form of one key.

Personally if I had a bunch of keys at the end of a session I would be heading over to the Ashen Garrisons to make use of 'em and get those emmy flags for Reaper comms.

Potential to add Ashen Key Lockboxes to all existing vaults in the Forts in the future.
Good loot within them.