I experimented with pin pressing for my press a bit a go, from about nose level. I just did pin presses instead of regular presses, and I got weaker.
My suggestion is if you do experiment with these movements, do them as accessory work after the normal movement. Check out some of the guy's threads/training logs working with Josh Bryant, as I have seen dead squats worked into his programming as maybe the 1st or 2nd accessory lift.
If I ever do it again, that's where I'm putting them in.