Deep litter needs contact with the ground in order for microbes to do the work, it won't work that way on a metal floor, and even in a real deep litter where the ground freezes all activities come to a halt through winter.
Agreed.... With the exception of worm bins natural microbes need to be able to breakdown the heap... As well as a good mix of greens vs brown with the nitrogen levels of chicken poop.. Can be done, but more research might be needed to help you along.