I've used the drill start method for donkeys years like Norm,gml, never had a problem and a lot of the time the socket gets stuck on the flywheel nut , so don't weld your extension to the socket,then remove the socket after shutting down the motor .
Just to test how safe this method is I once spun the socket up on a drill at full speed then hit the socket off with a lump of wood, the socket went virtually nowhere in distance just down to the ground,it's a similar concept when using a parting tool on a lathe the metal being parted off does not fly up and smack you in the face.
It wouldn't be too difficult to make a socket like a crank starter that disengages when the motor starts.
