I use the 1 1/2" Dremel EZ lock cutoff wheels with a flex attachment so I can get perpendicular to the track. I rarely need to dress GG but Atlas O is another story. On the Atlas cuts I drag a file across the burrs and that seems to be enough on the nickel/silver rails.
I place a small piece of plywood across the rails as a guide, when the EZ Lock hub rubs the wood I know I'm ready to begin the cut. I tap the joints closed first.