Dungeon Loot Modification - Proposed Fix/Tweak

I want to understand this better.

At the very least, you must store that the chest was opened and when, to set that timer. Do chests have an inherent data structure for that?

In addition, you also mentioned you are tracking on a per-chest basis which accounts and even IPs have opened that chest in the past (to prevent the same player opening them multiple times)? I am not looking for any details here but the assumption is that extra data also needs to be stored.

I had assumed that there would be a database of chests somewhere which tracked the timers to add new items and a lookup was done whenever a chest was opened, however you are telling me that this chest itself contains the data.

However, if I think I understand better, you have created a new entity internally, an extension of a normal chest, maybe we can call it 'RespawnLootChest', which is like a regular chest but stores additional data, ie the timer, history, and etc... This new entity is saved in the world data along with other entities like regular chests.

If that's how it works, this might be a simple workaround:
1) When the chest is broken, an entity which is an extension of bedrock is created at the bottom of the world (height 0) over top of an existing bedrock. This entity contains a copy of all the data, and otherwise acts like bedrock.
2) When the chunk is reloaded, that entity does the check and recreates the chest, copying the data back over.

Moral of the story if you don't want anyone else to get loot from the chest you found, make sure you destroy the chest too.

I believe loot chests can no longer be destroyed, which is what the OP doesn't like because the loot chests may get in the way of building.