If you want to save a bit on space, just go with the traditional grub-screw fitting on the drill instead of having the whole torque limiter setup in place. You can still have the torque limiting just by screwing the grubs down a little less than what you would for drive. It'll take a bit of trial and error though to find the sweet spot between having enough torque to swing the axe but limited enough to slip once you've hit something.