How do you expect the container to store the Type? I think that not storing the type would be very useful, but I miss how could the key retrieve the type after deserialization.

Also, I am pondering wheter the 4-8 byte loss in memory allocation (depending on compressed oops and alignment) and 1 byte on network is worth the code bloat with expanded class hierarchy. Therefore it would make sense to omit just filling in the entityOrRoleName