Dick,
I have spoken to literally dozens and dozens of ATCs and they have said that there is absolutely no doubt that C requires extra workload and extra responsibility when compared to E.
That is my point! The (VFR) aircraft are there, it's just that you "hide" them in E. They will still hit me with the same result if they are not talking to the ATC or me. It's just that nobody will be able to blame the system; it will be silly old (dead) me for not keeping a good lookout IAW CAR 166.
the US “implied clearance” (as you call it) is exactly the same in D or C. So there would be no change.
So you are not introducing "internationally proven" airspace at all, are you? From the same outfit that allows citizens to walk around with guns, not wear seatbelts for years after we had mandated them, and who drive on the wrong side of the road, you're introducing implied clearances into C CTRs. Hardly international
or commonsense.