I find that very interesting, because any time I have checked chicken feet, they always have the back toe pointing backward.My hours of close observation of chicken feet settling down on the roost shows that chickens like to sleep flat footed, all four toes forward, hanging a tad over the front edge.
They do this on narrow objects (the 1/2" thick edge of an upright piece of plywood, or the top of a fence board) and wider objects (2x2 board or the narrow edge of a 2x4, both really about 1 1/2" each way) and even wider objects (wide side of a 2x4, so really about 3 1/2" wide) and very wide objects (large flat piece of plywood, or the ground.)
So your statement that they have their back toe pointing forward has me really puzzled, because I've just never observed this. Maybe your chickens are different than the ones I've had?