I think the writer made some kind of mistake; his level 1 charger is running at HALF the normal charging speed. The picture shows he is getting 0.7 kw charge rate, but 1.3 kw is standard when you're plugged into a normal wall socket. I suspect the charger he is using is set to a lower charging rate and he didn't notice.
I had a 2013 LEAF and charged it from a normal wall socket for ten years; you get 50 miles of range, approximately, from an overnight charge. If you don't drive more than 50 miles a day, the Kona should be fine using just Level 1 charging. I have an Ioniq 5 now and still just plug it in to the same wall socket (in fact, I use the same Nissan Leaf charger, which I kept

)