I found something interesting when using Illustrator - and thought it might be a tidbit some might not know. Forgive me if it is listed somewhere else, but I couldn’t find it.
Illustrator gives you options on how your stroke sits in relation to its vector shape. It is an option called Align Stroke. You can align to the middle, inside, or outside. The default is Align to Middle.
On a recent piece, I happened to be using a 1pt stroke for the cut mark that was aligned to the inside. The resulting cut produced two cut lines 1pt apart. Once I changed the stroke alignment back to middle, the Glowforge produced the normal single cut.
Knowing is half the battle. Now I know.