I am installing a new FD-M590. The seat tube is 28.6 so I have the large shim on it which of course makes the clamp as large as it needs to be. When the cable clamp is installed correctly the flat rolled over bit which helps prevent the cable from rolling out to side contacts the seat tube clamp.

https://goo.gl/photos/xFMMM69NsGWVSoDA8

I believe I can file enough off the seat tube clamp to clear the cable clamp without any problems. That there is contact seems so odd that I wanted to check that I am not missing some other solution before I take the big hammer approach to Shimano's finely engineered bike part.

answered own question - tried to delete