So I tried this on the weekend with a badminton racquet. My first observation was that is was fairly challenging weaving the crosses on untensioned mains. A high chance of a misweave so I had to be extra cautious as I did it.
It also took about double the time from start to finish to string the racquet, as compared to doing it the normal way. Perhaps I would get faster if I tried it more. I did all of the prestringing with the racquet off of the machine.
The only thing I took from this experiment was the ease of getting though the shared holes. Perhaps in the future I would prestring the mains, and only the first few crosses that have shared holes. Otherwise, I can't see this method saving too much time.