IMHO, OTK’s seat position specs are somewhat vague and confusing as well as wonky to track across time. Highly recommended to base your seat position mostly off Tillett’s seat position guide, specifically using measurement D as well as front-to-back weight distribution percentage as your guiding beacons, combined with 4-wheel scaling the kart with the driver in it to ensure that you end up where you think/hope you’re ending up. (or you can be like me and drive the kart around for years only to find out that it’s always been 4-5% too far forward/back [a galaxy], and that all your other setup changes were just lipstick on a pig this whole time, lol)
There’s a lot more seat position commentary in this thread.