Yeah, i know that much at least, I'll always put luck modifier on my weapons/tools because of that trick. Only problem is, when i put my manyullyn bow in the enchantment table, not all enchant abilities are available to choose from, such as infinity/power/punch/ etc.. My guess is you just can't get certain abilities on the TConstruct weapons/tools, only some of them such as blood attuned/fortune/unbreakable/soul tether etc..