I touch mine up as I stated on the above thread at the IAP.I found a saw sharpener who charges $5.00 to do it when I feel it is really too far for a touch up.
what ever you do don't mess with the bevel on the flats.
When you think of it the barrel trimmer or pen mill is more important than any other tool used in turning a pen.
If the end of the blank is not perpendicular to the tube nothing about the pen will be right.
BTW the next pen mill I but will be sharpened professionally before I use it.
The one I had sharpened worked better than any new ones I have bought.
Stay away from the new Carbide trimmers.