Yes, like I said, Illustrator does a ton of extra work to try to keep you from shooting yourself in the foot. Programs that don’t cost an arm and a leg leave it up to the user. (But they usually use the even-odd rule which ends up making things work out. Because it’s easier.)
Illustrator ought to let you make a non-working example, but it might make you jump through some hoops to do so. I don’t know; it’s been years since I last used it.
In any other program it’s trivial to make a file that the GF chokes on. Many of us do it by accident all the time.
Here’s a quick example I made in AD (but you could do it in Inkscape just as easily and it should be easy in CorelDraw too).
As you can see, with the even-odd fill rule it doesn’t matter whether paths are clockwise or counterclockwise. But with the non-zero rule it makes a huge difference. So when people using programs other than illustrator make a shape using even-odd fill rule (and with Affinity Designer the Subtract operation always generates a shape using even-odd fill!) it matters a lot that the Glowforge treats it as if it used the non-zero rule! It means whatever is in the right column ends up looking like the left column on the Glowforge. Not a problem if you happen to have paths with alternating directions (bottom row) but a big problem indeed if the paths go the same direction (top row)!
And here you can see how the Glowforge mangles it:
Only the top-left shape should be solid. The other three should all have holes. But because Glowforge can’t handle the even-odd fill rule, the top-right shape is not rendered correctly.