Yes, it is random. If you select 100, then change to another value, then go back to 100, you'll see a different set of patches.
By the way, if you want to carve the patches themselves, instead of the lines, you can make 2 copies of your original shape, one a fill and one an outline. Then run the app on one of the shapes and set its cut depth to 0 after adding it to the canvas. Then set the original fill to the same position as the imported object. Finally, bring the original outline to front, and set its position to the same as the imported object. Here's an animated GIF of the process.
A little clunkier than it needs to be, but it gets the job done