I have a question about the retainer boost potion. One of my friends has started this game as a machinist and skipped all the beginning stuff to start at Stormblood. I assume this means he will have access to retainers too -- but since he will start as a MCH, will boosting his retainers make them also start as a level 60 MCH?

He asked me and I had no idea because I leveled mine the hard and free way