Oh come on, Lefi doesn't mess up salt and sugar in the novel. Her clumsiness was well explained as that do to her insanely high stats she has trouble adjusting her strength with delicate tasks. She struggles with mixing as she splashes it all over, eggs as she just crushes them, cutting as rip counter. Taste based things like salt and sugar she has no problems with, she also is pretty much constantly using appraisal so no way she would make that mistake. That is a very dumb change the manga has made.