Wang, I never really had that probem with the "3", but I sure did the same thing as you, flying the banner looking aft, with one hand on the throttle pushing as hard as I can, and another hand on the release, man those hot summer days!
I remember pulling over the ATL speedway at a Nascar race, I had just re-hooked and refueled flying a SuperCub. It felt like I picked up the van instead of a banner, this thing seemed like about 45 letters. All I remember was the tail flag just barely wiggling over roofs of cars out in that immense parking lot, sweet talking the airplane for altitude(with a few choice words also). I must have made a complete circuit around the track before I made 500ft, I was far outside the track to, out over the pines, while all the time my hand on the release.
I must have a million of those kinds of stories, maybe we should collaborate on a book.
"THE LIFE AND TIMES OF A BANNER TOWER"