Currently there's no way to get Item entities that were killed due to falling out of the world (Y < -128). In my case I'm need to teleport any entity from that location to the world's spawn, and listening to EntityDamageEvent with DamageCause.VOID currently works fine for any entity except for Items — they are just gets despawned silently w/o any event.

So I suggest to implement a Cause enum (NATURAL/DEFAULT and OUT_OF_WORLD) for ItemDespawnEvent (this will be better I think) or call EntityDamageEvent for Item entities too (this will probably be easier).

Thanks!