Old school, I use a 3D Gorton pantograph to engrave some stuff, have looked at lasers.
My take is it depends on the shop and how you want it engraved. A top shop with a 4th axis can probably do anything right around the butt. A small shop with a ~$200 laser & no other live fixturing can probably only do flat work, or work in an area small enough radially to count as flat (say 1/4" around the circumference). Or a line that is not too wide, straight along the cap parallel to the stick center. A manual index fixture could be used 1 letter at a time around the butt, just like a non-interconnected fixture on a manual panto.
Lasers sure have changed the possibilities, though!
smt