a bit of trivia....
many years ago I was the guest on Kaye Woods PBS TV show and the project was for her to teach me how to do the "6 Hour Quilt". It is my recollection that one can indeed do it if there are no interruptions during the process and you know exactly what is to be done and how to do it. You can't spend time answering the phone or taking care of other personal needs when the clock starts and the serger works perfectly. One would most likely need to have all the strips cut and work space in order before starting and might be able to work up to the 6 hour time frame. It is a really neat and easy quilt to do.
It's a little like my "Quick-n-Easy, No Piecing" crib quilt I make. I had to time it one time for volunteer hours for the hospital where I donated them. . I did it completely in 3 hours which was really conservative on time. Four hours would have been better.
So......it's like anything we do - the more we do the better and faster we become. BTW. That year I was able to do 100 for the hospital.