Have you ever placed torches with your offhand while trying to place a block with your main hand? Do you think your offhand could be "smarter"? Well, this is what this mod has to offer. When the items held in both your hands are right-clickable on blocks, your offhand will be disabled. Items right-clickable on blocks include: blocks, torches, stairs, slabs, redstone, doors, flint & steel, shovels, hoes, minecarts, leads and seeds. As of version 0.2, holding a consumable item (food or potion), will also disable your offhand.
A mod for Minecraft 1.12.2. All files in this repository are licensed under the terms of the LGPL 3.0, which can be found here: https://www.gnu.org/licenses/lgpl-3.0.txt