The article is cool, and it is fun to build a custom version - just sharing a little more info on this.

They've had this feature out of the box on a few Bambu models for quite a while now. It was part of the H2 series, and the A2L is them expanding it to the cheaper models.

The printers come with software to lay out text/drawings, line up the paper with the overhead camera, and run the job. And it comes with a tacky plate to hold the paper in place while drawing. It's all pretty slick - no need to mess with custom g-code or anything. You use the same process whether you are drawing, using a drag knife, or laser cutting.