Now Im really scratching my head. What in specifically EVO's geometry would cause that?
Outboard lower control arms that have a lot of downward angle at ride height. This happens when you keep the axle lowers below the axle line, but have the frame lowers up in a high clearance position above the frame rail. Lots of kits have this problem, it's not just EVO. It's what happens when you make a long arm kit but aren't willing to do a ton of fab work to make it awesome, which is obviously what plenty of kits do.
This creates crazy bad rear steer.
Companies like Synergy solve this in their long arm kit by having the frame lowers sitting down below the frames, but then you lose ground clearance.
If you want it all with high ground clearance and low rear steer, you have to have your axle lowers at the axle tube height to keep the links flatter. If you really want to nearly eliminate rear steer, you have to inboard the frame side of the lower control arms, but that obviously means gas tank relocation which the kits just don't want to do. Only one that actually does a truly excellent suspension is the Genright elite kit.
That said, I used to have a lot of rear steer, my RAA angle was double-digit in the rear (recently decreased it a ton but still far from zero). I never had a problem before where I wished I had less rear steer. Sure anyone can find a video of someone rock crawling and say "if they didn't have severe rear steer, it would have done that line". Ok great, but for every one of those videos, you can also come up with a scenario where having rear steer actually helps you keep your line. At the end of the day you just have to know how to drive your rig and compensate for what weird things it's going to do. Nice if you don't have rear steer, but it's not as bad as some people make it out to be in my opinion. There are other much more important reasons to have flat lower links.