As it happens - every time I use the machine! But only because I use the same switch for home and limit. Initial homing is done at some fraction of machine speed, and experience says that the physical machine limits can take the load if all else fails. Although that has only been tested rarely, I'm glad to say. On the router, max limit switches never get tested (apart from Z, obviously, as that's where it homes) but the mill does not have any. Have to rely on soft limits there.