While on a server that was updated to the latest version, I found that the recipes would duplicate the items in the crafting fields. It applied to both inventory and crafting table crafting grids, and when I rolled back the version to v8.0.2 the duplication bug was gone. During testing I had 2 blocks of gold, when shift clicking the result I managed to get 16 STACKS of 4096 ( 16 slots of 2x Gold upgrade Sophistocated Storage chests) of Gold blocks in addition to the 3 stacks of gold ingots.
Below is an image of the amount of blocks received, I ended up trashing a lot of them when I realized that there were still over a thousand more on the ground.

I'm uh, not sure how that makes any sense. The only change there was removing an override that was identical to vanilla minus the call to the new awardUsedRecipes method, which needed to be called anyway.
I suspect mixins are afoot...

Oh, no, that's why - awardUsedRecipes nulls out the cached recipe, for some godforsaken reason.

Why is vanilla's crafting grid code so awful

This is the greatest thing I've read today