RudyGarmischNot even close.
Not necessarily true since they aren't mounted yet. Have them mounted for a bsl that falls in the middle of both of yours and you will be fine. Have them mounted for a 311 mm bsl and you will have no problem adjusting the forward pressure to accommodate both boot lengths. My roommate and I share some of our prototype skis and neither of us will ride anything but an FKS at a resort. I have a 308 mm bsl, he has a 296 mm. We mount for a 302 mm and we have enough adjustability in either direction. I have read that pivots have a total of 19 mm of adjustability, so 9.5 mm in either direction for a proper mount. Based on my experience, I don't quite buy that range, but 6 mm in either direction isn't an issue. Also, take mounting location into account if you do this. You wouldn't want to mount at center because the person with the smaller boot will be riding forward.