I think you answered your own question. You need both fronts and rears to have the same level of grip in order for the kart to function properly. Steering by using snap-oversteer and using the throttle modulation on the way out is slow and sloppy.
If anything you want to rotate the kart on the way into the turn by modulating the brakes (trail brake) and then gradually introduce the throttle. You can ‘fix’ the understeer problem by over-slowing into the corner to get the front to hook up. But you’ll be slower than everyone else.