Not to beleaguer the point, but why provide a "2-user license key" at all if the 2-user ADS version has no time restrictions by virtue of the setup file itself?
Likewise, I've always been able to update my developer installation using the latest versions of standard ADS setup files downloaded from the maintenance site. This would seem to indicate that the license information entered during setup determines the number of users and any appropriate dates, not the installation file. That just doesn't seem to be the case for the 2-user license key.