I used only the BVM UAT but also used the BVM header tank that comes with the Bobcat in the wing. It fits great and adds either 12 or 16 oz. I draw from the wing tank first and the main tank last. Wing tank catches the air from the main tank when it gets almost empty. My main tank is bone dry when flight is over! Unless you fly from pavement exclusively I, personally, wouldn't add the CompARF wing tank! It does make it heavy on takeoff, especially in grass, and is not necessary to get a reasonable flight time.

I added their tank after changing to a P120! Almost finished with a second Flash but using a Titan this time!