Another case is when the kart enters the bend properly, but becomes too reactive or the rear end loses grip easily in the mid-/exiting the bend sections. To counteract excessive reactivity, it may be necessary to work on the front end, doing the opposite to what you would do to reduce understeer: therefore, reduce the front track or reduce the caster angle.
On the other hand, to make the rear end more stable, especially mid-bend and then during acceleration, you can try reducing (a few mm at a time) the rear track. Alternatively, you can try fitting a more rigid axle or longer wheel hubs.
Whereas in the first case the modification leads to greater rear end instability during braking, the second modification does not have any major effects on the first section of a bend, although it needs to be said that the latter modifications take longer to carry out.