One thing to understand: Unlike everywhere else where IFR and VFR flight plans are handled very differently (i.e. IFR flight plans go to ATC, VFR flight plans stay with flight service), inside the SFRA/FRZ, VFR and IFR flight plans are both handled by Potomac Tracon. An SFRA/FRZ VFR flight plan is just an IFR flight plan with a VFR altitude and special remarks. All FRZ flight plans have a special code in the remarks that confirms the FSS specialist confirmed the identity of the filer. As such, it's possible to do things like file an IFR flight plan but depart using that flight plan under visual flight rules, and potentially never pick up the IFR flight plan if you choose. Whether you're IFR or VFR, you're talking to the same people through the process. The difference is controllers don't have to worry about separation when you'r eVFR. They still have to talk to you, and you have to be squawking a non-1200 transponder code. That's why the term "transponder observed" exists; it allows them to acknowledge a VFR aircraft's transponder is squawking the right code without saying "radar contact", which would imply they are providing radar service and traffic advisories. Occasionally Potomac tracon will open up controller positions that just handle VFRs to reduce the workload of controllers working all the IFR arrivals and departures. Otherwise VFR folks are talking to the same controllers handling everything else.