I had my current transmission completely cryo'd front to back.
I went back to the cryo shop for some more work and discussed our application to him in detail. I was surprised at his honesty, but thankful at the same time.
I was told that the cryo'ing process wouldn't prevent me from breaking output shafts during a stall test. He actually went on to say he didn't even think it would hold to more torque before letting go. He said the cryo'ing process is amazing for how it makes the wear resistance go up on parts. But the only way a shaft or torsionally loaded member would be stronger, is if there was some residual stress from building the piece. He told me the cryo'ing process relieves residual stresses, but the additional strength for input and output shafts would not be worth mentioning.
Not if, but when I break this input shaft or hub, it'll be my third. Then I plan on installing the billet stuff that DTT sells.
-Chris