Press and DL thoughts....
One thing about these two movements I've noticed is that they typically increase along with others. Increase your bench, your press comes along. Increase your Squat, DL goes up.
I've noticed with me that high 1RM%(90%) DL training is unnecessary to increase your dl Max. Sub maximal work spread over a longer period of time peaking every 2 months, works well for me. I think this has to do with keeping the neurological pathways the DL uses fresh by still working it weekly and hard, but not tearing up my nervous system by constantly attempting new PR's. Working hard, but only really having to go balls out once every 6-8 weeks is effective.
Another thing I've noticed is that Presses and DL start with the concentric segment and ends with the eccentric, i.e the negative of the movement is after the lift is completed. Whereas in the squat or bench it's the opposite, the negative portion comes first, followed by the lift. What does this mean? Who the hell knows. Controlling the decent of a squat or BP is important, and in many ways decides the execution of the lift, where this element is absent from a DL/Press. I practice a lot of singles in the DL/press because of this lack of the negatives necessity in a successful lift(if I can lift it, I can set it down), but then again if your after multiple rep max's this is a moot point...and who knows if that's why this singles business works at all...Different and progressive are just as likely culprits...blah blah blah..thought I'd ramble..