Neutral is where the sway bar wants to be with no load on it. Ideally the sway bar would be in a neutral unloaded state when the Jeep is sitting flat side to side.
Reviving an old thread as I ran into something similar this week.
@jjvw is absolutely correct. The links should be adjusted so that the load on the swaybar is neutral when the jeep is at rest (unloaded).
I spoke with Dirk at DPG Offroad this morning. I don't think there's a more knowledgeable person on JKS' product line, and he confirmed this sentiment.
Something else to note, depending on what coils you run, a minor sag on the passenger is considered normal. For example, I run OME coils, and the driver side coil is roughly 10mm taller to account for the drivers weight (passenger side rear coil has the same 10mm offset to account for drivetrain torque).
When installing my quick disco's, my passenger side disco is roughly .25" - .50" shorter (adjusted in freedom units) which roughly equates to the 10mm difference in coil height. Again, all normal and by design (certainly for OME coils).