I was thinking the same thing.
To expand on your idea - if you have, say, three MapPoint licences, could you track/locate/monitor up to three vehicles in real-time and impose the 16s artificial delay on any others?
The reason I am interested in this idea is that in my application (which does use SMS by the way), a delay of up to a minute is usually acceptable, but from time to time I would like to reduce this delay to a minimum.

Also, what does 'user' mean in this sense? Is it a human being or any application program integrated with the MapPoint software? You might have to make sure your delay is imposed before it reaches this application.