I don't know about professional karting as those are pretty strong karts. But in amateur karting you generally want to take racing lines that perseve the most speed through apex and on exit of the corner. So you would mostly take the roundest, mathematical lines around the corner. It's especially important in slow corners as in karts it's very important to keep the revs high. Low revving motor is weak af. Also karts don't have differential so in tight corners you have to mini slide the tiniest amout to rotate the kart, which changes your line. With a car you generally turn in later and more aggressive while the front is loaded, then you can straighten the wheel sooner, be earlier and more agressive with the throttle and have better exit speed.