but it's a very safe, stable and essential part of a bushplane's flight envelope on the basis of mine.
I don't think that "very safe, stable" describes hydroplaning wheel planes down the middle of a lake. "Essential" sure doesn't. The only essential running down the middle of a lake without stopping, is water pickups for waterbombing, and that Maule was not doing that! He was out goofing around. Not that some of us haven't goofed around, but we sure should not be celebrating it.
Serious, responsible bush pilots avoid factors and operations which have risk with no benefit. Bush pilots typically operate in the middle of nowhere, so any small risk becomes big, just because no help is close by. Running lakes on wheels is a stunt, not bushflying.