Daggerboard placement is also very dependent on the sideways resistance of the hull as a whole. For example the Taipan design has the board further back than a design with the much more rounded bow section. With the Taipan the hull itself forward of the mainbeam tends to act as a daggerboard itself making it necessray to place the daggerboards further back to compensate. So it dependent on the behaviour of your hulls too.

It is never simple.

Wouter