Originally Posted by jpatters
When the jib boom pivot location on the boom is moved , it changes the rate at which the jib swings in and out with sheet tension. So the jib or main boom sheet attachment locations may also need to be changed to keep the jib's movement synched with the mainsail's movement as desired. Stock Nirvana sheet-boom attachment locations are fixed, so they may also need to be changed to adjustable like in the super Nirvana pic.
oh...oh...now it's getting more complicated....