The reason for associated types over generics for embedded_can

[Thom-de-Jong]

Why does the embedded_can, Can trait use an associated type for the frame?

I want to link two libraries, each implementing their own can-bus and can-frame type, compatible with the Can and Frame traits, but a can frame from one can't be send to the other... Is there a way to make this work or do I have to manually convert between the types.