OPS I AM SORRY
Now we know that MEG must works alone without GWX 3.0 . The only solution for the moment that you have (if you want) is make on pc two installations of SH3...so one is with GWX 3.0 and you can play alone when you are off line and The second installation with MEG you can will use when you play on line so the time for loading a mission will be more short !!
MEG 1.0 it's only in the initial stages

we are working now for
MEG 2.0 (next version) that will be the
first upgrade we are increasing the sound and graphics effects !