Indeed, my first guess was the crop growing system but then I found out it doesn’t fit my needs… I looked around on the other systems and the food decay is the only one that I felt could be of use to me.
Here’s an overview of what my system requires:
- Items must change to another entity after a while;
- Items are affected anywhere (inside containers, inventories, on the world)
- The entity they change to must be different if they’re in a container or dropped on the ground/stockpiles
It’s pretty much the same as Food_Decay with the addition of the “different” entity thing, which I did manage to come up with myself since the Food_Decay service has a check (IF… in storage…) and it wasn’t that hard to figure out how to edit it, so I almost managed to create the system I wanted.
The only problem is that bug from the Food_Decay system itself, where items do not decay if placed in a container right after being crafted (without ever “existing” in the world itself)
As for creating my own component, maybe it could indeed be simpler/cleaner, possibly… But I’m afraid I don’t have the skill to create one from scratch yet 
I could try, but creating a new service based on Food_Decay seemed easier for that purpose