In props, There are so many variables, that it is a trial and error process to fine tune the plane's overall performance.

Sometimes you are limited by what props are available to you then there is also the cost consideration.

To get the seaplane off the water is more of a static thrust situation. But as the plane picks up a little airspeed, static thrust is not so meaningful.

Buy yourself a fish scale and make your own static thrust measurements. Then you can tell us what works best for you?

Enjoy

Jim