I am about to start a new frame with white oak 3x7.5 braces. The braces on outside walls will be pushed to the outside 1.5" tenon, 1.5" shoulder. For the interior, however, I am thinking of putting them on center. When a brace is housed on the center of a post is it common to put a 3/4" shoulder on each side of a central tenon or cut them exactly as the outside wall braces? Also, I have read old barn frames often have no pegs since the builders understood bracing in pairs put them in compression. If this is so, why peg them today? What function does a brace peg serve? Thanks