I've got good news and bad news.....
But first some history.
I had bad death wobble when I first bought the Jeep in April. It was in need of bushings, tires, and suspension work so the DW wasn't really a surprise. I replaced pretty much all the bushings up front of the Rubicon Express lift (using OEM rubber bushings). I also got it aligned. Turns out I only had 2 degrees of caster!
What the *$%@??
I have adjustable uppers so I removed them to shorten them. They were bottomed out and couldn't get shorter. So I called RE and asked them about this. First of all, they suggested between 4 and 7 degrees of caster. Secondly, they said that the Rubicon models require longer uppers. So what they do is sell everyone the longer uppers and non-Rubicon owners can just cut some threads off in order to get the uppers short enough to get the caster into spec.
So that's what I did. I cut the uppers as short as I could and re-installed them. Well, for the most part my DW was pretty gone after all this work....and new tires.
Fast forward to today. I decided to get an alignment for the first time in awhile. Turns out my cutting and shortening of the uppers only netted me an additional degree so now I'm "up" to 3 degrees of caster.
So I feel confident now in saying that the lack of caster is really the reason I'm getting DW, not because of the new wheels. That's the good news, i.e. I have a culprit for the DW.
I can't shorten the uppers any further, though. That's the bad news. What else can I do in the meantime until I have time to build my long arm suspension? I decided to remove a 1" spacer from my front coils in order to lower the suspension and likely get some caster back. Turns out it helped. The slight wobble I get is lessened and is now at a different speed. So at the very least, it made a difference. That's encouraging.
Now the Jeep is driveable, but isn't great. But it's good enough to wait another 2 weeks until I'm in the new house and can start fabbing up the suspension.