I previously had a 2014 TEP without KDSS. I installed Bilstein 5100s all around and put the front adjustables on the 1.75" setting. No modification to the rear height at first---just installed the rear 5100s by themselves.

The body and fender angles/heights absolutely appeared dead level, and I ran that setup for a few weeks. But something just didn't quite feel right to me. When I really started crawling around and more closely scrutinizing my vehicle, I confirmed that the frame actually did have a slight "negative rake" with that setup. I really don't think that it would've caused any problems, but it just made my OCD hurt to think about leaving it that way.

So I installed a 20mm OME trim spacer on each rear coil, and (for me) that totally solved the problem. The result was a truly leveled T4R---even when hauling a full load or towing a small trailer.

Hope that helps.