Use thinnest section which is strong enough
all the camber and washout really means nothing on this type model
it's- just -too -small
Wing loading is EVERYTHING
All the fiddling with sections and twists is just an attempt to fix overweight conditions
Build more - theorize less - you will learn more.
Not trying to minimize others opinions - but having built hundreds of different setups - the only real fix I have found ,is to build as light and strong as possible . Theairfoil shape stuff including sharp vs round LE- simply of little or no actual value
fudging the planform to increae tip chord IS of value