It could make a difference of more than 2cm if you have no setback and fore placement on the rails, and they have 25mm setback with aft placement on the rails.

6'0" with 35" cycling inseam, 79.8cm saddle height from center BB to center of saddle. straight seatpost. my hips don't rock-- I can pedal seated to 120+ rpm without issue. (I work it on a trainer. ) I haven't measured the angle of my knee at the bottom of the pedal stroke, but I doubt it's the 30 degrees DaveSSS was talking about, maybe more like 20.

a vid of you pedaling on a trainer (or on the road, if possible) would answer this. but it's really easy to experiment and just find out for yourself. I set my saddle height for years and knew what I wanted, and it so happens to be close to Lemond's .883 suggestion.

if it feels wrong, don't settle. make sure to measure and take notes, otherwise you can be hunting up and down without success. if you log everything, you should be able to zero in on it.