I've not seen that the airplane has built in washout. And I've not seen one to know, but it's picture looks like it's a straight taper wing. Those things naturally stall from the fuselage out anyway. And it looks like a symmetrical airfoil. You do not want to mechanically twist a symmetrical airfoil. The Tower specifications don't mention washout. That'd make sense, if it is a straight taper and symmetrical.

They do mention using the ailerons as flaperons. I really don't think anyone would want to do that with a tapered wing. So that also suggests it's a straight wing.

I really like your idea about airfoiling the stab/elevator and fin/rudder. Just looking at the airplane just now..... It looks pretty, but the bracing on the tail ruins it for me. It's like fingernails on a blackboard to me. It's a cheap way to strengthen something that should have been designed better. In real life, it's usually a cheaper way to build. Or done when cantilever is beyond the ability of the mfg or the workforce.

Looking forward to some construction pictures.............