Peter Dohm wrote:
the effect of variable camber.

The same can be done with the vertical tail, although the only place
I have personally seen it was a Folker Triplane replica. It flew
quite well, at the hands of a very good pilot, but what I saw
indicated that I was NOT qualified to try it. (Back then, planes
flew much closer to people on the ground, and observers could be
quite close to the runway, so the required rudder work was more
visible.)

Peter

The 601XL I'm building has an all flying vertical tail.

www.peoamerica.net/N601WR