I personally think its wheel bearing tightness. I have not had the death wobbles for years, after having it and replacing everything. The last resort was put new stub axles in as I noticed a small step where the inner wheel bearing sat, right against where the hub seal ran. after I replaced the stub axles all was good. This was some 8 years ago I think. The wobbles were recently slowly coming back, I jacked up the front and both wheels felt good, I gave both wheel bearings an extra one only notch to tighten them up. All wobbles were gone.
So my theory is the wheel bearings need to be slightly tighter than you think, especially if your running larger tyres.
But. If you need help with anything. Shout out. If I'm able, I'll help.