The very idea of using a contol surface that extends to the wingtip as a flap is crazy. I have 18,000 hours mostly flying corporate jets and a lot of stuff we do with models makes me scratch my head. I have been using "spolierons" on this Extra. It seems to work good for killing the float on a landing, but I can't believe that it isn't more violent or effective. I guess its the power to weight ratio thing. I have mistakenly taken off with 10mm. of spoileron, (both ailerons tipping up), and hardly noticed the difference. Maybee I have numb thumbs eh?