Very clever and the video is well done. I built one that was modeled after one in a Fine Woodworking article and it worked pretty good but was out just a tiny bit. And that is one of the problems with these type jigs is that if they are, there is no adjustment. Mine used a keyway. I suppose I could have removed the key and sanded one side and shimmed the other and it would have been perfect then. But one of the other disadvantages is that you are stuck with one size. If you are doing a smaller project that needs a smaller tooth then you need to make another jig. And the last disadvantage is that you have to match the saw blade width to the jig, as in the same thickness dado stack. If it's off a bit then you need to play with it to get it right.
The Ibox jig takes care of all of that. I was lucky enough to find one on Amazon Canada for $149 our money so I jumped on that deal.
By the way, you can use a finger joint jig for making dentil molding (or a much simplified version of the jig. It isn't nearly as fussy as making finger joints). Adding dentil molding can really add some class to certain projects.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.