I don't want to buy a stud punch just for one small job, so is there any other way to run romex in metal studs legally besides punching holes and putting in the yellow plastic grommets? This is a new wall added in a residential home.
The Golden Rule - "The man with the gold makes the rule"
I never run romex in metal studs. Never! Too many sharp edges and tooooo many careless fellow tradespeople. I notice that even if I do a stand up job installing any cable, someone comes along after me and screws it up by pulling on it or leaning smoething on it or running something by it.
I would even go as far as punching / grommeting and still use mc cable.