Again it is all personal preference , but as a easy guide look at the fin primer as to where I place my centre fin.
My instinct is not to place the centre fin on a line that get close to the rear of the base of the side bites as this would make a wall of fin base and probably make the board track more as there would be difficulty for any sideways release of water flow and odd turbulence .
If you look my centre fin is about 25mm or 1" back from the base of the side bites, I also believe and I have never checked it out that side bites and a centre fin fully back in the box would also be some sort of odd ball experiment, probably with the side bites grabbing at inopportune moments in the nature of the pivot turns the way back fin requires.
The BLEF Roy Stuart fin whale tubercle fin works best for me as a single right back in the box, pivot absolutely and at a higher point on the wave face NICE
