I agree with the assumption that it's the recentered wheels. There are a lot of variables that can add up to throwing the wheel to far out of balance,
-the welded centers
-how centered is the tire when installed on the rim
-How ballanced is the double bead lock PVC insert
-The welded rock ring...
I went with the TWF recentered, 4"bs with the flat centers. I had to add spacers to the front because the centers hit the caliper. I still need to "try" and get them somewhat balanced. Death wobble at ~35mph:steer: