The more I look around, at full scales and other rc flying boats, I've come to the conclusion that the hull design on the Wave King
may not be the best.

Most flying boats seem to have a significant portion of the bow above waterline at rest. The Wave King has all but the very end of the bow in the water. I think this makes it more likely that it will plow with the slightest chop.

Do you know of best design practices for seaplanes in this regard?

Perhaps I should reshape the bow to allow more of the planing surface to extend above water?