Another way to cut the folding miter is to use a dado blade tilted to 45 degrees. That's what I was going to do in the first place, before I noticed the V-groove bit. The V-groove bit takes longer to make the cuts, though, and router bits get dull a lot faster than blades. While it takes some time to cut the folding miters, it takes no time at all to assemble - just fold and tape the miters. This method would work just as well for larger drawers made from thicker plywood, but you'd want to use that dado blade instead of the router bit to speed things up.
