Update: I spent 3 hours waiting around at the dealership today. The guy tells me that the technician couldn't feel what I was talking about. I said, "I'll get in the truck with him and I can make it happen right away." Then he said, "well, let me see if another technician can drive it and see what he says". After about 30 minutes they come back to me and say, "He felt the problem, and agrees with you that because it's a smooth ride in neutral, this isn't a suspension or tire problem. Our engine and transmission guy is booked today, so you'll need to make another appointment to drop off the car."... Man I hate this place.
The 2 new tires that have ~1500 miles on them are starting to show the same wear pattern. I'm almost ready to get rid of this truck. What a pain.