Rigging a Zoom: seat (re) placement?

[Einar]

Two female friends (150 lbs?) both own Zooms. I have paddled a Zoom for several days, just not one of these particular hulls.

One of my friends Zoom was brought over to my shop for modifications and before starting any changes I measured what exists and then, a little puzzled, I had the second Zoom brought over for a reference.

In both Zooms (112" length overall) the vertical backs of the seats were set at 48" from the stern, and 65" from the bow, definitely stern biased from 56"centre.
(Neither of these Zooms are professionaly rigged, they were done by previous owners (nothing wrong with that, done many hulls myself)

Starting from basics in any hull I usually install the seat with the vertical back 4" back from hull centre, putting the mass of my torso in centre hull. Yes, I agree individual hulls can be tweaked forward and back for preference but these Zooms seem to be way out, with the seat too far back by 4" at 52" torso centre instead of 56" torso centre

The question: is this standard rigging on Zooms, this much stern bias of 4"? How did you rig yours?

In personal experience the Zoom is fun: dry thru holes and surfs great in the pocket on medium waves. If this stern bias is standard seat placement for the hull I don't want to take anything away with changes. It is just my opinion, not my boat.

Thanks for any info.
Einar