>>>There is NO incidence or COG problems with a Flying boat.<<<<

That's only true if the FB is designed and assembled properly. The Herr Aquastar, for one, needs a lot of modifications and tweaks to its design for decent surface handling. As-designed it is more of a bad atomizer than an airplane. Add power, The nose goes under, the prop gets water from over the bow, and there's a big cloud of spray where the airplane should be. And when this happens, a lot of water gets inside and if by some miracle you get it airborne you will have MASSIVE CG problems when you start to climb and the slug of water rushes to the tail.

It can be fixed, but you imply that Flying boats are automatically perfect due to their floating hull design which is just not true.

The aquastar really needs a wider forebody to the hull (the patch is spray rails), and it needs more upthust, and I'd bet a round of cold brewskis that it would be happier with more wing (and stabilizer) incidence.