My suggestion to Mike Smith at the time, relating to the above experience thus terminal E airspace, was why not have a requirement to have VFR call the tower (they are required to be on freq anyways) with self announce of who they are, where they are, and where they intend to go. This way the controller is aware of them and their intentions and can offer seperation guidance as appropriate?? Terminal E is gone, but the same could be said for enroute class E... no requirement for a clearance, just a requirement to announce what you are doing.
My sources tell me this was one of the options for the rollback; but alas it proved to be more workload intensive than making it class C again (separation is easier than 'guidance' as essentially you as an ATC carry the same 'risk') and also there was the added risk posed by deliberate non-compliance with the call in process.