You know Joe I was thinking the same thing. I really don't believe that the little amount of carnauba in PwC affects the sealants at all. I have used it under UPP, ExP and #26 without any problems aswell as Natty's, P21S and S100 (which is b/c of carnauba and carnauba). I find PwC to give off a better look than PP aswell. Just my thoughts.... maybe Steve could clarify.
Side note- Since I'm thinking about it, PwC and AIO both give protection and no one has said any about issues with Sealants not bonding with AIO so that makes me curious. Maybe the difference is in the acrylic in AIO?