Can anyone provide any pointers on how to achieve the following behavior for air drops / chinook crates?

I would like a PvP bubble to appear around them on spawn (on the ground is fine), and remain until a couple of minutes after they despawn.

I tried setting the following:
- 90 second stop delay
- 900 second duration
- start when spawned
- stop when killed

...but I noticed that the PvP zone was gone from a crate while it was still active.

Do I just need to set an extremely long event duration, like 8 hours or something?

Update: More testing needed, but setting event duration to zero seems like it might work - spawning an air drop immediately results in a PvP zone, and it goes away when the drop is looted.

This revealed another issue, though: DynamicPVP doesn't seem to create zones around drops/crates that exist when the server starts up. This isn't the end of the world - it just means pre-existing aidrops and Dome crates would be pacifist contests on my server lol.