Rear Sway Bar Position?
 

I just installed RSR Sports i's on a 2018 BRZ. I used the standard recommended specs from RSR for all of the adjustments. I'm not sure exactly how much lower I am now, but I believe the sway bars have changed positions (pushed up in the rear and down in the front). I ordered adjustable end links for both front and rear. What I found is the new rear end links are nearly the same length fully adjusted to the short end as the OEM links. The rear sway bar pivots freely in both directions through a pretty broad range, in other words pre load does not seem to be an issue in the rear, unless I am not understanding preload. Do I need to be concerned with the position of the rear sway bar? This is all very new to me, so I appreciate any help. I have not removed the front sway bars yet, I may have some more questions on those later. Thanks.

As far as I understand adjustable end links are important when corner balancing, which typically leads to different ride heights on each wheel which introduces pre-load on the anti-roll bars. The adjustable end links allow you to have different end link length on each end of the bar to remove the pre-load.
If you are just lowered, there is no pre-load on the bars and nothing is rubbing/hitting suspension parts you should be fine with OEM end links.