Interesting, but I could not listen to that guy. I vaguely remember hearing about something similar in the past - related to making cheese dip. I think I'll look into it more this wkend.
I don't tell the folks at the show, but for the deli american I use velveeta. This time, rather than use any variety of american cheese, I added 6g sodium citrate after the noodles finished cooking, and then mixed in 8oz of grated cheddar a small handful at a time. It turned out well. I consider it a good proof of concept, and I'll have to try it for for some other cheese sauces.
I did make that beer cheese (and didn't like it). Maybe I'll try that mac and cheese above. I've got the noodle extruder, so maybe I'll do 100% scratch.