The wander/tram-lining is going to be very tire dependent as well. I have a very similar setup on my truck and find some tires tram-line a lot worse than others. I've had 275/40-17 street tires with 360 tread wear ratings that caused terrible wandering and road race tires in the same size that tracked straight as an arrow.

The other thing that contributes is bump steer. The tall lower BJs get rid of most of it but there's still about 1/8" of misalignment there that causes bump steer. I think the effect is amplified by wide tires and minimal toe-in.