I cut out all the panels, then changed to a dado blade and set the fence for the middle. Cut them all at once. Be sure to mark your boards which side needs the dado. For boards with dadoes on each side, I just did one. I nailed a cleat on to hold the brace on the butt joint side. I just did not want to thin the board that much in the center. Next time I'll probably go 1/16 deep instead of 1/8.
The time saved in sizing and installing the braces is enormous. Driving brads into them is a little problematic, but with some creative clamping, no brads required.
