Inventory Tabs obscure the Reforge Gear tab in the anvil. Clicking on this "double tab" crashes the game. I strongly suggest against adding tabs to an anvil and instead use a separate block for reforging. Or maybe repurpose the grindstone. But do not add tabs please.

Added a tab config with 5d73732 to disable/remove the reforge tab. I have no plans to add a separate reforging block

Any update on making this compatible? I think you can modify it so that clicking on the hammer icon in the anvil switches it between anvil mode and reforging mode.

I have no plans to make it compatible with inventory tabs. Might change in the future.