My Major has an after market ignition switch fitted. When I wired it up, I made it so that you had to hold the key in the start position(spring loaded part) AND push down on the starter engagement lever, for her to turn over.
I too was guilty of standing in front of the rear wheel to start her prior to the rewire.

Now I need to be seated on the tractor to start her.
Haven't tried it with the original switch though, as she never had one when I got her.
Kiwi Kev