Hi Savoia,
cool idea - offers job possibilities for some - but I guess to expensive ;-)
Three out of four contakt is actually what I do most times.
But even with both hands on the grip, you´re going to hurt yourself, if the remaining foot looses grip, because your weight is over the platform to move the other foot down.
Yes, we have a plattformladder for the tailrotorcheck - but you can´t use it for the main rotor and hydraulics.
I took a closer look onto the onbuild steps. The antiskidmaterial worn and overpainted - may be that contributed....
Greetings Flying Bull