What they all said.
And I always say you can never have too much starch. ;-)
I remember years ago a friend calling me in tears because she couldn't get the borders on her Blooming 9-Patch to lie flat .
(The quilt is made up of over 250 3-3/4" blocks on point)
Turns out she used HST's instead of QST's for the setting triangles, so the edges on the queen-size quilt were all really unstable.
As in psycho unstable.
It was a nightmare.
But we chuckled about it.
After.
So even if you plan on putting another border on after the braid, I'd still recommend you stay stitching the outside braid edge.