Coming down at minimum touchdown speed the banner wil touch while the a/c is still quite high up -- at which point the drag will decelerate and stall the a/c and whip it into the oggin
Whichever flap setting you decide upon, make sure they won't block the doors which will of course be opened before touchdown.
As for touchdown, once you enter ground effect it's time to ease the nose up as far as it will go without ballooning. Mind you a wave or swell will likely make the first contact and the a/c must still be flown to a complete stop.