I think this should be more positive than the switch on the leg. The adjustment is not at all critical, if I need a bit more slack before the switch trips, no problem, there's lots of travel in the spring pulley. Also important to me is having the bridge totally seated. I was having issues trying to get it fully seated before the motor cut off. This should eliminate that issue entirely as once the line starts to go slack, the bridge isn't moving any more.
Just waiting on the wire I need to run from the controller to the new limit switch. 
