If I understand correctly, the dust deputy, cyclone, thein separator and all of those dust separator artifacts their only purpose is to separate dust from air. They won't increase your cfm.
Specially in my case that I mostly cut (I'm planing to hook it to a TS) MDF, when I cut it it generates a huge amount of airborne dust all over the room. I need to be able to catch all I can before it gets everywhere. That is why I think a vac wont do, since it doesn't create an air flow, it just sucks whatever is close to the hose, nothing else.