Well, I once suggested charter flights, but I cannot see, how implementing another suggestion to pass this one might help. I mean - a plane for GA can easily be a charter plane and vice versa - even a CA plane. Why add confusion that a single plane model either uses AvGas AND JetFuel just depending on the type of flight?
With that logic, a Learjet would use AvGas only if used as GA and JetFuel if used either as Charter and CA. Adding to the confusion is the fact, that charter flights already are counted as GA flights in a certain way. So…charter flights are the only ones using the correct fuel and both CA and GA will have a chance to use the wrong fuel all the time with your suggestion. A propeller plane used as CA (hypothetically and totally possible) suddenly needs JetFuel and a private jet plane as the Cirrus has to use AvGas if used as GA flight. If that is not confusing, then what?