Something to consider: I've had the 4-corners of the suspension balanced as close as possible side-to-side by adjusting the TBs and adding shims under the leafs (all this was done as though the car would be in race condition: driver, ~1/3 tank of gas, empty trunk, etc). We found that balancing the corner weights of the car with the sway bar end links disconnected would make a difference, then... re-attach the end links and make them equal in length with the end links... by adding bushing washers to the end link as needed. I've only used the factory design end links, so again, I'd use washers as spacers to equalize the end link distances, as well as equalize the torsional effect, as the car would sit at rest, of the sway bar AFTER the car was balanced side-to-side. Without the washers and NOT being concerned of the corner weights of the car, the sway bar will have an affect on the corner weights of the car.

So, having adjustable end links to equalize the distances, at rest, is an advantage in end link design. In other words, you don't want one end link pre-tensioning that side of the car over the other side of the car... it causes a small amount of pre-weight transfer that you don't want to have.

Setting up your car with respect to this matter will simply help another increment in overall "fine-tuning" of the handling.