You don't have to have 1/3 speed food at every meal but it is recommended. If you look at the 2015 Food Optimising book, SW says beans on toast is a perfectly acceptable meal without any speed foods. Generally, where your meal includes a Healthy Extra, you don't need any speed because the HEx has already put a limit on the calories you'll consume.
The purpose of Speed foods is to reduce the amount of Free foods you eat. If you were to have your beans on a jacket potato, then speed food should be included, the idea being that they will help fill you up and you'll choose a smaller potato and/or leave some because you're satisfied.