So, I’m thinking a LOT of this might be a combination of the JTech Plugin and/or Repetier-Host.
First picture is something I cut last night. It missed some lines, elsewhere on there is a straight line that isn’t in my image (but is in the gcode previewer in Repetier).
I set it in inkscape to do 42mm by 15 mm…and it came out somewhere near 21 inches by 8 inches. Can post the gcode later if anyone wants to take a look. Some I attribute to lack of smoke clearing. When I have a fan turned on blowing onto the laser, it does much better. But my fan doesn’t provide 21 inches of coverage so some spots the smoke lingered and the laser got caught in it. Better fan connected to the laser mount absolutely needed!