J Tech Laser Etch Software / Pic Engrave Pro Setup

I have a question on the Laser Etch Software (Appears to be same with Pic Engrave Pro).

I have a large sign (24" Wide by 8" heigh) that I want to “burn” into some wood. I created the sign in Inkscape. The PX setting is 2160 x 720 which converts to 24x8 if I choose in unit of measure. When I load the drawing into either of the mentioned software packages and set the pixel resolution to .1 (as recommended by the software) my “engraved” image is roughly 1/3 the original size. I tried using paint.net to make the image “larger” but would get out of memory error on my computer. I would need to set the resolution to .28mm to get it to the proper size. They seem to recommend .05 - .1 for best results.

Has anyone else seen this? How do you overcome the issue? Does .28mm really make a difference in the engraving?

I am running the trial version and the engraving is lines with gaps in it. Not sure if this is the 50% code for trial or if this is a result of the .28mm. (This is with J-tech software)