Figured I'd follow up on this.
Finally had time to reinstall the KW's. Ordered a second set of upper strut mounts for the front so I wouldn't have to keep disassembling and reassembling the front strut assemblies.
I've been taking a slow methodical approach to sorting this out but unfortunately based on what I have found in the Mini forums it seems like a problem with Mini sourced half-shafts. I can only assume that because our X1 shares a Mini chassis we are getting half-shafts that have a tight operating range.
Here's just one example of a thread I found where people are complaining about the same issues Proper and I are having.
https://www.minitorque.com/forum/f84...owering-11406/
And that goes all the way back to 2010!! So this issue has been going on for over ten years almost! Surprised KW hasn't at least put out a bulletin or something.
So back to what I am doing, I reinstalled the front KW's only and lowered the front approx. 2.5" and the vibration was still there although it appeared to be more subtle. I ended up reinstalling the rear KW's and set them about 90% to their full upper ride height. The vibration still stayed subtle. I am now playing with lowering the ride height in the front since our other member here (Proper) is riding quite low and states his vibration starts to go away as his fuel is depleted.
It'll be the weekend before I can play with the ride heights more but I set the fronts at full max upper ride height and the rears at about 110% full upper ride height (this means the collar is hanging off about 1/2" of the rear perch) and for reference the max overall ride height you can get (all the way up) with the KW's still give you 1.5" drop in the rear and approx. 1.25" drop in the front. And the ride becomes super tight!
I'm literally almost to the point of just dumping the KW's but I really want to see if we can sort this out somehow.
Attaching a pic of KW fronts installed only.