Time marches on, and new information and ideas surface. When EI was started most people didn't try to dose more iron, so the list of dosages didn't include any, beyond that in CSM+B. Now, more people are finding that extra iron can be very helpful, so the latest dosage tables list iron. K2SO4 is useful if your tap water is high in nitrates. You can reduce the KNO3 dosing and make up the difference with K2SO4 for more potassium.
If you look at EI as more of a way of thinking about fertilizer dosing - always have more than enough of every nutrient available to the plants, and rely on big water changes if needed to avoid building up any dangerous level of any of the nutrients - you can be pretty flexible with it. Dose every day, dose twice a week, dose weekly, dose extra potassium, dose extra phosphate, etc. Do bigger water changes less often, do smaller water changes more often. Do few water changes at all. The table is a great starting point.