Cool idea
The website to get a jump on buying one is :
https://comingsoon-tech.com/goliath-autonomous-cnc-machine/
Youtube video is pretty short and not useful
Looks like they use some sort of positioning pillars that are placed on the corners of your work area to guide this thing around.
I do see a couple of problems. One is debris control. As the wheels roll over debris this thing is going to tilt around like a drunk.