Two Illustrator pro tips:
- Create a 20"x12" default size (or, if you like, a 19"x11" one with a half-inch of bleed around the edges). It’ll place itself in the GF UI more or less where it is in Illustrator.
- Disable “Responsive” SVG output. There’s one checkbox for the default SVG output, and one for the Export for Screens option, which I prefer. Unchecked, it’ll cut/engrave things at the correct size; checked, at 80%.