So you CAN get both, we do it on wavekites typically.
Of course you can calculate the amount of "work" needed, which might be constant in theory, yes, because of a bit longer "throw".
But only when initiating a turn of the kite, not necessarily when it actually turns, nor when you dont turn the kite - and in all instances, the static FORCE will be higher.
So the average amount of force needed will be much smaller, if you move the rear lines further aft
Having a longer bar dont really work IMO - only if a really big kite where you angle the bar extreme, otherwise it does not help.
The stress can actually increase with a longer bar - as it is harder when you hold your hand(s) close to the center
And the reason for bad shoulders and elbows and tendonitis etc, is the force that is stressing
So just sew some more aft attachment points to the kite
And as mentioned - be aware if the tip buckles, but you'll find out and can just move them forward again if the case.
Peter