You probably do not need to dose it. No, the CSM+B does not have calcium, but the calcium is plentiful in the tap water for most US residents. Yes, plants do use calcium, but it's only a trace element used by plants and they use very little daily.
edit: If you want to though, you can forego K2SO4 and get GH booster instead. That will dose Ca and Mg as well as potassium, and is what most EI users do nowadays, I believe.