Wouldn't you always need a new mold for every length?
For Stockli it would cost a fortune to build that many molds because of the complexity of the mold. There separate molds of each size of each ski.
The press system has to be reset for every length as well.
It gets really costly in both time and materials to do that many sizes. Stockli pressing of the special gluing system already takes longer and is more costly, but if Stockli keeps growing at the current rate it might become feasible in the not to distant future to see tighter breaks like 7cm on more of the freeride skis. Currently only some of the race skis are grouped at 5cm.