So I only want items set to true to decay if they are outside TC range regardless of upkeep.
"Check empty cupboard": true,

Do I set this to false or is this meant to auto decay everything even if in TC range?

No, If it is true and TC has no resources, the entities in the range of TC will decay.

Is it possible to make it only check if it's in TC range? I pretty much want to use this for automatic (time-specific) deployable cleanup.

Someone reported to me that they forgot wood in their TC (which was just for a stability bunker) and it started decaying boxes/workbench/etc that I had set Enable Destroy to true on.

"Check empty cupboard": false,//Set it to false