Honestly, the a lot of his episodes are just "buy this one thing, and all your woodworking problems will end!" but this one got me.
I usually just make squared doors like a normal human, but I think the 15° bevel may just be the answer to a problem I didn't know I had.
I have a router table I made this winter, and I'm redoing my kitchen (any day now) so I just ordered these. No idea if they'll be worth it, but he got me.