i think you can do the same thing using a sheet of plastic wrap with your design on it. pin that to the top of your sandwich. use one of the horseshoe-shaped open "hoop"s. they have rubber on the underside that should allow you to move the quilt around. or - once you draw your design on clear plastic wrap and pin it in place - why can't you just use quilter's gloves with the little rubber bumps?
this actually looks more complicated than it needs to be.
i think inventors deliberately make things complicated so you think they're special and then charge lot, when something simple will work. have you ever seen them in use?