Logically you are correct, the other end of teh leaf springs should also be extended, but when i talked to friends they say it wont make much of a difference.
So far I am struggling with tires rubbing the wells at the back end of the rig on turning as there is very little space there, and i have come to KHI so the process is halted currently. Once i am back i need to get the spring leaf raised to manage the sag at the rear end.
On the tarmac, the ride has actually improved with softer tires and the road noise has increased (very enjoyable), but all in all the stability so far is good. I did some off roading with the shackles in front and rear with steelies and ndcc tires, they worked quiet well and without any stability issues.
I want to get the leaf springs TARred up so that i can see where we stand, then if needed, i may extend the other side of the shackles and maybe need to move the brackets as well. Lets see what the Kamani expert suggests.