Mythic Archmage Crafting Mastery

Question

The Archmage Mythic path has an ability called Crafting Mastery. The wording says

Crafting Mastery (Ex): You can craft any magic item as if you had the necessary item creation feats. If you actually have the item creation feat needed for a magic item you're crafting, whenever you attempt a skill check to create that item, roll twice and use the higher result, and you make twice as much progress on the item for any time spent. This ability does not reduce the item's cost or any other requirements.

Am I correct in assuming the bolded section also only applies if you also have the item creation feat? How would this effect something like cooperative crafting with your familiar if you had the valet familiar archetype or a non-mythic helper? It would likely never happen but for the sake of rounded question what if the helper also had this ability and was mythic?

Answer 1

To realize that benefit of the special ability crafting mastery, the item creation feat is necessary and the creator must be crafting the magic item himself. That complex sentence needs to be pulled apart to show the effects, but when that's done, here's what happens:

If you actually have the item creation feat needed for a magic item you're crafting,… you make twice as much progress on the item for any time spent.

Thus, were a creator that possesses this special ability to realize its benefit also to have an assistant that possesses the feat Cooperative Crafting, the creator would, essentially, quadruple his progress.

However, a creature that possesses the special ability crafting mastery and that aids a magic item's creator in crafting a magic item does not grant the benefit of the special ability crafting mastery to the magic item's creator. The creature with the special ability must be crafting the item itself to gain the special ability's benefits.