I hit an interesting bug with shift-click and the furnace. I forget the exact quantities, but let’s say I had 5 sap and 2 bones in the furnace, ready to create 2 glue before running out to bones. I shift-clicked 9 bones from my inventory into the furnace, but those 9 disappeared and the furnace showed the same materials. Then, I shift-clicked 29 sap, and those also disappeared. I yelled briefly at my computer and wrote it off as a bug.
Then I added fuel to my furnace and started crafting, but I made all 11 glue. Now it showed nothing in the inventory, but it said “Crafting: Glue” and gave the “Missing crafting ingredients” error. Sure enough, I went and got a bone and it crafted 1 glue. It’s as if the shift-clicked items were added to the furnace but are not accounted for in the stacks I can see in the UI. I’ve still got a couple dozen mystery sap that I’m occasionally adding bones to to make glue.