We probably shouldn't worry too much about this, as long as we don't know what's really going on.
We speculate about how we could push the limit further away, that might be worthwhile.
But I was thinking about characters. They have handles too. If they take the handles from the same pool as items, then spawning or summoning characters alone could cause the crash, although it might take a lot longer than 550 hours ;-)
My 'field bed skill' also spawns an item, maybe I should no longer have it talk, because that might lead people into over-using the skill just for fun ;-)