I have the same exact 1-18 washer as Nate except in Harvest Gold...a Model WC. The Maxi water level stops about 3/4 of the way up the upper cone, an inch below the top "ring" on the agitator.
FWIW, I tried washing my stuffed Full comforter in my machine, and it didn't do much. Thick items like this are better suited to the double-loaders at the laundromat. I think Nate said something at the wash-in about having good results with his, which surprised me.
You probably should think about attending a wash-in sometime if you're interested in learning more about a certain machine. Many times when you see that machine in person you answer your own questions right there just by looking at it and examining it. There's definitely nothing wrong with posting questions, but trying to find out every single minute detail can sometimes come across as a bit Gwisdalian (LOL). Also, while it is nice every once in a while, not everyone has the time to make a video of their machine...I know I don't! So it may take some time.
And that is a COOL 16-pound Magic Chef...it may be BOL, but it sure is SWEET. With the narrower tub, I bet that agitator can make some waves!
Austin