Good friend of mine has a 1/4 Cub on floats and fly's it with an old, tired G23 and it fly's scale, but well. I had a 1/4 Cub which was all scaled up for competition with a full body pilot and all the works and at 17 lbs I flew it at half throttle most of the time, including scale take-off (land only, not floats) on a DLE-20. People have gotten so power happy over the last several years.
Sucks about the cowl though, I'd probably get a smaller engine just to avoid cutting the cowl up too much.