Waffle house grits aren’t usually sweet. I have never had grits with sugar on them.(Lived in the South my whole life) I think @Sherpa had a rogue Waffle house cook.
When I make cheese grits I just follow the directions on the box and then add butter, cheese (any kind that I have around-sometimes I try to use up what is on hand) and salt and pepper. Sometimes crumbled bacon on top. I use quick grits -but not usually instant.