My rabbits, inside or outside, are on 1/2" x 1/2"vinyl covered hardware cloth, thus all refuse passes through the wireon to the paper lined tray below, or the the ground in the case of theoutdoor hutches.
The relatively small size of the openings precludes any sore hock problem, yet permits feces to pass through quite adequately.
You may want to consider cutting out your floor and installing wirehardware cloth in a similar manner. My outdoor hutches aresuspended upon wheels, by the way, so they may be moved about the yardout of inclement weather and to prevent urine/feces build-up in any onespecific area.
Buck