Originally Posted by vpiuva
Actually, since your milling "both" sides of the post, you're only taking 0.2mm thickness off. The post would probably take it, but I think I'd look for a correct one first. I've sanded a 27.0 down to a 26.8 before. Started with 60 grit and gradually moved to finer grits and steel wool. Looked great but it was a cheap non-fluted post to start with.
How deep are the flutes, and how good do you envision them looking 0.2mm shallower? (May not be able to tell that little amount in reality)
As for the flutes, pretty deep and I wouldn't go as far as the flutes. My thoughts were to go just above the insertion line and then taper to the flutes. I've already measured where I want the seatpost height to where I want it. Anyways, I'm never going to replace the seatpost after that because it took me forever to find this particular post. Problem is they never made this particular one in a 26.4. The smallest they made was 26.6.