Dan, I’m also 6’2 and I had to work a bit to find a decent seat position this year. I’m on a compkart, but the same things might hold true for you. I’ve experienced the same issues as you where on turn in the front outside tire gets overloaded by excess jacking, due to a combination of my height and too much camber.
I had a T11 copy in the kart to start and I feel like i sit on top of the seat and have to use so much energy to stay in the kart, so I swapped to a T8 standard.
My seat is just over 5MM below the rails, it picks up a decent amount of rubber. It’s also reclined a touch. I have wound up almost 1″ behind where J3 had me start with the seat. Between getting the seat into the right area and pulling caster out of the kart I’ve found the front end to gain a lot of grip. Before, as soon as you’d turn in the rear inside would jack immediately and the front outside would overload quickly due to the height of my body’s CG transferring more weight than needed. Mid corner off would usually be oversteer because as soon as I’d touch the gas the rear inside would slam down and flat slide to the exit.
Get your seat low, and be gentle with the throttle on exit.