Create any spell with a 'break' effect, and put it in your off-hand. In your main-hand, equip any tool (not necessarily a pickaxe) which is enchanted. From Astral Sorcery, equip a Resplendent Prism or select a perk which boosts one of the enchantments on the tool. When you right-click to cast the Break spell, for every block that gets broken, the boost on the enchantment becomes permanent, and is then immediately boosted again. Using a Pierce+AOE Break spell and a strong enough boost, I can gain around 100 levels of Fortune per cast.

The issue is caused by lines 72 and 93 of '.../spell/effect/break.java'; EnchantmentHelper.getEnchantments() doesn't realize that the enchantments it's reading are incorrect. This could be fixed by modifying a copy of the held item, rather than a reference to the item that actually exists, and also moving the enchantment modifications outside of the posList loop.

Should be fixed now, thanks!