I have been looking at buying these skis and I have also been trying to figure out where to mount em if i do get em. Since they will ski like a symmetrical ski on groomers, i figured if you go further forward and your not spending a shitload of time in the BC riding/landing switch, you will end up riding what will feel like a forward mounted symmetrical ski (since you wont be able to utilize the portion of the tip that is rockered) and that would ski like ass i bet.
So, IMO, if you ride/land switch a lot in the BC and you are barely on groomers, consider going a little forward of recommended as to utilize the extra length with the rockered tip and to help balance out the switch riding.
If you are spending a lot of time on groomers, consider how a symmetrical ski is going to ride when its mounted forward of the center of the normal cambered portion. I'm not totally sure how that would ride, but its something to think about and consider.