Okay so you know all about EMT. You go to Wisconsin with their Romex and seems wrong. I mean to me. Issue is in far north Lake/Mchenry counties people will get Romex anyway. The AHJ knows nothing if they are not called in. The fire inspector probably knows better. I do not think Romex or even Greenfield are safe. If I had to choose between having EMT or AFCI’s I would take the EMT. Maybe I am an idiot. The fill % is for heat and friction. For the record the NEC to current AFAIK allows for 14AWG on a 15A OCPD. It also allows #12 to first receptacle of 20A and subsequent 15A pigtailed with #14. I fully agree That lower is a good thing. Look how many people are doing jobs just back stabbing everything. You get what you pay for. Those cheap cookie cutter homes good thing now they do have AFCI’s I guess. Except putting Smokies on GFCI LOL.