fin to elevon gap... depending on combat damage about 1/8th of an inch, the TE of both the elevon and the fin are the same untill it moves as the fin has a v shape at the rear with less fin on the bottom, unlike my GF's fins on her smaller Mamba which are mirrored.
the section is differnt from other Vipers, i think it has more reflex, the bottom has a slight curve all the way and the top rear stops comming down and flattens out. when i brought it from Soar Ahead Sailplanes (SAS or sore head sailplanes if you fly with us )
I was told this improved the turns with less speed droped, its true i can turn tight and almost seem to gain speed, but its rare and three turns quick turns later you better give up or crash. unlike the others who push on. i think bigger fins and using lighter correx may help, maybe more nose weight to loose the tail heavy like handling