A strange bug seems to be caused by disabling repairing, steps to reproduce are;
Step 1 • Set allowRepairs to false in the config.
Step 2 • Launch game.
Step 3 • Place item in table and try to scroll down the enchantment list (while in creative.) You should see that you can't scroll through them.
Step 4 • Set an enchantment to any level on the item but don't click enchant. You should now see that you can scroll the enchantments, really odd.

Repairing has been removed in 1.12.2 in favor of the anvil.