My Theorems:
* Creation and subsequent destruction of variable numbers of non-like-typed items may create FPS loss (IE. create 10 bins, create 9 mugs, destroy 3 bins, create 10 bins, destroy 3 mugs, create 9 mugs, destroy 15 bins, destroy 10 mugs, create....etc) such that entire sets of item-creation jobs are not being immediately destroyed, and could possibly create empty vector indices within the lists as it is not guaranteed that an entire stack of a created good are destroyed entirely, which could, and logically would, free up the memory location if done haphazardly.
* Corollary to the above: or at least a simplification of it. Each job set of a specific non-unique item could be creating a list set in the item vector list. If the above holds true then destroying only part of the list would not necessarily free up the memory associated with said list set to allow that set to be used for something else. Iff, (if and only if) the entirety of the item-set is destroyed the memory is freed.
I think this is the problem. To show what I am talking about I am going to mention my first "successfull" adventure carecter.
The water flask (or waterskin or whatever) you get when you start an adventure guy holds three water. Normaly when you go to drink it says waterskin (3) or whatever saying how much water you have. One day I drank two of the three water and refilled the waterskin when I noticed something like this (note, none of this is exact, its midnight and I am not loading the game right now to worry about it).
waterskin (2)
water
Which means this. When I first filled the waterskin it created a stack of three water. I drank two of the three water. So the item list went like this.
water (3)
to
water
When I refilled the waterskin instead of combining the stack of two water with the water already there it instead created this setup.
water (2)
water
Therefore creating TWO enteries in the item list because the system does not combine like items in inventories like it should. Logicaly it should have combined them into water (3). BUT the game does not do that and instead kept the old entry of water and just added a new entry of water (2).
These errors can easily add up over time and decrease FPS while increasing file save size. Will do more !SCIENCE! tomarrow to see if this continues.
*edit*
Confirmed. Instead of combining like entries the system creates a new entry. Tested several different ways in adventure mode.