Downhaul Comparisons by Common Measurement

I've just got interested in fine-tuning my downhaul, to the point of putting some markers on the sail where the leach looseness disappears, and comparing session to session. It got me thinking - would there be merit in sharing/posting some 'leach looseness' measurements for the same sails on seabreeze for interest and the assistance of those like me trying to calibrate whether my downhaul is 'in the zone' or whether I need to man up and pull another 2cm of downhaul on?

I'm thinking there only needs to be one basic measure; the distance from the last point of looseness in the panel, to the front of the mast, when measured parallel to the battens, in the second panel down from the top of the sail. If I took my most used sail, a NP RS Slalom Mk II 6.7, it might (just plucking a number) have a measurement of 32cm as described above. If several others, when reporting details for the same sail, quoted numbers several cm less (ie leach looseness is further advanced forward, towards the mast), it would give me a good pointer to try more downhaul, drive the looseness a couple cm further forward, and see how it feels.

Any merit (or interest) in such a concept?

Sail manufacturers usually have a setup/tuning guide on their websites. And each designer usually sticks to the same setup over all their designs.
If you are so inclined read them all and compare.

My experience tells me no cam wave and free ride sails are best tuned from positioning of batten above boom where batten touches mast, batten near centre of mast equals min down haul. Batten barely touches mast max down haul.

Cam sails looseness in 2nd panel 2/3rds in as a start then get anal from there.