Update: Nothing conclusive but I did some experimenting today. I increased sag from 25mm to 28mm (not sure this did much), decreased tire pressure from 34F/35R to 32F/33R, set the dynamic damper setting to harder and the shock setting to softer.
Started w/ 4 miles of twisties, felt great. Wind dead calm, but enough cars & trucks to create some air movement on the highway. Went onto highway and sought out as much turbulence as I could find with as light a grip pressure as possible. Much much better after about 15 miles (out & back) I then changed the shock up two levels to harder (from softer to harder) and did it again. I knew within 2 miles I had just made it worse, so I immediately went back down to softer in the back. By stiffening the steering damper and softening the rear, I perceived that when getting buffeted, it calms down much quicker. It's not perfect, but I had no confidence issues at all which is something I couldn't say yesterday.
Theory: As said above, I don't think the tire was slipping I just perceived it to be. I think maybe the hard tires and the faster shock rebound were causing a countersteering movement that I was perceiving as slippage.