Back to the EVO high clearance arms, the lowers on the axle side are raised substantially over stock. But I'll take a look at raising them in line with the axle tube. I would be concerned that then the uppers would be too low.
Honestly, I'd probably focus more on dialing anti-squat than worrying about rear steer. Do you know where your anti-squat is right now? I've never run the numbers seeing that I can't personally measure anything, but pictures of the Evo high-clearance rear long arm always looked to me like the instant center is way too far back leaving a very high anti-squat, possibly well above 100% which would be a big problem for good performance. I recently dropped from about 100% to around 80% and the difference is tremendous for highspeed desert use (wouldn't really even notice crawling, maybe a tiny bit less hop when spinning up ledges).