Messes up the slots for the Crafting Station; it appears to keep the same visual appearance but have the interaction model of the inventory screen - clicking slightly right of the lower right slot put a block into my offhand slot. The Crafting Station seems to register some clicks still though - repeated clicks seem to sometimes work in the same slot, though not for the middle column. Love the idea, hope you can get it working with TiCon interfaces :).

Edit: Forge 1.11.2 ... 2315

Having this issue as well with the 1.11.2 - 3.1.1 version.

Here is how they look with the TiCon GUIs. Hope this helps with bugfixing!