Yes, I can enter the serial numbers during installation without problem. And, yes, G2 is just like G4 and presumably G3 in that you have to register to update but, the other similarity is that you also can't use the list server until you register. So, yes, you are correct that MP can still be used in G2 because, unlike G4.5, you are able to specify a particular session host by IP and port to connect to a private session that doesn't require the use of the list server.