Elevons..
I didn't go per plan..I left the TE of the wing square and put the tri-stock on the elevon. It just looked funny the other way to me. I know many had been built without the benefit of my kit bashing, but I just went with what I was used to.
Also....and this is just speculation, I don't want to get into an aerodynamics lecture...my elevons were thinner than the TE of the wing, so I replaced them with some 5/16" thick TE stock. I did this after reading about Dave McDonalds flutter problems with his DDust until he went with thicker elevons. I don't know if it was needed, I think I remember the kit mfg. going to thicker stock in later kits. But mine never fluttered and I flew it WFO all the time, full power dives and all.
I had 5 CA hinges on each elevon, with one directly under the control horn..the horn screws went thru the CA hinge...to keep it from deflecting under load. Don't know if it was needed, but it never fluttered.
This is just how I did it...I'm not trying to sway your decision as to how you do yours.