Well said. You are particularly on the mark when you said, “it is tricky to optimize an airfoil for any set of operating conditions”. Since the vast majority of data are for Re’s well beyond anything we usually design, dick Hanson’s cut and try approach with a little intuition thrown in is about as good as any.

I just have one observation. While a flat plate works fine for a flip-flop type aerobat (it’s symmetrical you know), A slight leading edge camber will result in a more efficient airfoil at moderate lift coefficients. It will allow a little higher angle of attack before stalling and has the added advantage of providing more stiffness to the wing.