Andre makes it look easy because he's been cutting for 20 years, not because of the board. Put that same foam board in the hands of a guy who can't hold his clippers steady and you'll get a crooked line just as fast as comb work, maybe faster. The board doesn't cut the hair, your wrist and your angles do, and if you don't have that down no tool is saving you. Watch what happens when a walk-in sits down with a cowlick or a weird head shape, that flat board can't read the head like your comb can. I've seen guys lean on these boards for a year and their freehand fades get worse because they stopped training their eyes. It's a crutch, plain and simple, and crutches are fine until you have to run.