Zertz looks like a good idea but that isn't sufficient. I have no
experience with them.

My 'cross bike has a low end carbon FSA (SLC?) seatpost. I use
a cheap Al post for when I put the bike up in the workstand and
I have compared them on the road. The carbon is smoother but
I don't think enough to matter. It is a nuissance (sp??) to tighten
so it won't slip and won't be destroyed. I wouldn't do it again.