Note that J. Kenji Lopez-Alt at Serious Eats actually did find a faster way to fully caramelize onions. About 20 minutes, with the same scientific result happening (and, according to my experience, a tastier result).

http://www.seriouseats.com/2011/01/the-food-lab-real-french-onion-dip-homemade-super-bowl-recipe.html