There are two separate night flying endorsements. One is for private pilots who have completed their flight training in Alaska, and have then completed night training. This confers no privileges but must be shown to an examiner to have a certificate reissued without the night flying limitation.
The night flight endorsement which would be useful in this case is the one which is more commonly given to a student pilot, which allows solo night flight, subject to limitations. In the twin example, an instructor could also issue an endorsement to act as PIC of an airplane for which the pilot is not rated, which would allow the pilot to fly solo before licence issue by JAA in exactly the same way.
This is different from a complex endorsement, as they would have student privileges only. No passengers, etc.