that's stupid because you'll end up mounting in front of center because the tips are wider than the tails making the front heavier than the back so you'll have some great tip dive, mount them at recommended, the recommend that spot for a reason
I would go one or two cm back. however if the line is at dead center do that. I like to have the skinniest part of the ski under or just behind the ball of my foot, since this is where the most energy is transfered, and where you ballence regardless of weather or not you are skiing forward or backwards.
the rocker isnt in the center so it wont affect the amount of rocker whatsoever if you mount them 14, rather then center, if your not gonna be riding pow switch alot and landing switch in pow, then id reccomend them to be mounted at about -3, if you really feel its necessary then put them center, but youll still be able to land switch in pow with them a little farther back.