The standard versions of UCCNC have never done a double homing, so perhaps the Stepcraft version was using a custom macro? That's the only way to do it, I think.
Lowering your backoff speed should be all you need to do, though, to get more accuracy. UCCNC sets the home position when the machine backs off the switch, not when it hits the switch. So double homing shouldn't be any more accurate than single homing.