When the whole “hang the hub off the end of the axle” thing became popular in karting I thought there was no way this is right but we have been running like that for years and I have never lost a hub assembly off the axle.
The funny thing is *if* the hub is left loose or the pinch bolt breaks the hub moves in and not out which seems crazy but has always been my experience.
My rule of thumb is never let the pinch bolt be closer than a 1/4″ or so from the axle end like Gary said. Always have axle under the entire pinch bolt plus a little extra axle and tighten it down.
The only time I ever see a wheel come off is when someone leaves the 3 hub bolts loose and that’s definitely a big no-no.