Designated Start option

Have any contests used the "Designated Start option" ?

7.4 STARTING
7.4.1 Definitions
Start Point - is the midpoint of the Start Line or center of the Start
Ring.
Designated Start - is the use of a set of possible start times, beginning
with the original time of opening of the Start (see 7.4.5a), and
including additional times at regular intervals thereafter.
Start Time - is either:

the time the competitor crosses the Start Line or leaves the Start
Ring, interpolated to the nearest second, or

if the Designated Start option is in effect, the Designated Start time
immediately before the time the competitor crosses the Start Line.
7.4.2 Start Options The Organisers may implement the Designated
Start option. To do this, the Organisers must make an announcement
at Briefing and publish the “Designated Start Interval� on the Task
Sheet. The published interval must be 10, 20, or 30 minutes.