General rules for my fin cluster:
the closer the fins are together the looser the board
the further up on the board the whole cluster is placed the looser the board.
the further apart the cluster the turns will be more drawn out, stiffer.
given where your inquiry is located, in this thread, the powerbox center getting play as useful , instead of my take which is still, stupid, how do, I characterize a fin that doesn't move, so the center fin is always forward or always back.
given that the adjustment on sides is maximum , what , .5 cm, and some boxes zero, this isn't a mind boggling exercise.
The fins themselves are more interesting.
for turning you want bigger fins in the side boxes, smaller center fin.For speed a bigger center. By having all 3 fins the same or nearly the same size, this is to me the pure definition of loose.This setup on an Angulo, had some tri fin traits,but you would think was a twin. It tracked ok, not like a tri,it was fast, it turned really well, upwind not as good as a 2+1 tri setup. The best feel was a moderation of this, so a about 15cm center and 13cm sides.
YMMV
