This is the way we've ended cutting curved knee braces. These end up being 3'4" long.
http://woodsshop.com/PROJECTS/Mill/Construction%20Mill/CutKneeBraces.htmUsed to cut them freehand, and then tried using a template and flush trim bits but that's alot of extra work with all the belt sanding you need to do.
Cut them with a trammel arm and they're practically ready to go. We just lightly sand the bandsaw marks to retain the texture.
I never use tenons, but you could pre-cut them like we do the 45* cuts at each end.(pic #3)
We (two guys) did these 8 braces recently, including the sanding and drilling in under 7 hours.