I have a question myself actually. On the xbox, it takes some time to type in the custom names for enchanted items. does that cut into the time that the enchanting potion is lasting for? or does it pause the 'timer'?
While you are naming an item, the game gets paused, so it will NOT cut into your potion duration time. I've tested this myself. I've been able to enchant four items before my potion's duration ran out, and that's with two enchantments each. So you can take as much time as you need to name each of your items.