Ah... my Wise Friends... I have learned two important things these past few days:
1. There is a secret to fabricating perfect butterfly corners; and
2. I do not know this secret.
Oh... and twisted cord is the Devil's Own Invention. First join didn't look too bad, but the second looks like cr@p. Haven't decided yet if I should tear out that section and splice in another (= two joins instead of one, but hopefully will look better).