I have a drop safe in my recording studio that the clients drop their rent checks into. I believe that one of the nastiest thing you can do with a Medeco (or for that matter, any decent cam lock) is...
...set the cam so turning the key takes a bit of torque. Kinda like the dialing torque setting on an S&G combination lock. Medeco keys are pretty tough, so if you get the tension right it shouldn't endanger the key.
But it totally screws up feedback from your tension wrench, even if you have a fancy sprung one.

Anyone heard of this kind of thing? (Obviously it won't work with doors/containers where you can apply a prybar to bend the cam loose, but if your container is subject to that attack, why are you wasting a Medeco on it?)