It's me again, your friendly inventories bug finder

First, I thank you for fixing the trash inventory size setup for assembling machines : I tested it and it works fine.
However it seems to be broken for labs.
By default, the labs create a trash inventory when an item spoils inside the lab. This behavior can be seen here :
When no item has spoiled inside the lab : When an item has spoiled inside the lab : ----------------------------
However, when I try to alter the prototype to set trash_inventory_size = 3
On the screenshot below, the item has spoiled into a placeholder item that spoils into itself.
The normal behavior of a lab, from what I've seen, is that the item spoils and the spoil_result goes in the "trash inventory".
However, when I put trash_inventory_size = 3, the item spoils "in place" and the spoil result stays in the same slot. Regards