That probably captures many such things but it's not fool proof. I like to make bread with 2-4 different kinds of flour, 4-8 different kinds of seeds, a teaspoon or two of sugar to get the yeast going, sometimes milk or olive oil or another fat source. At it's most complex it could get pretty close to 20 ingredients but I don't feel that should be classified as ultra-processed. The kinds of ingredients used and the actual process also matters.