It could be part of the "logic" that it doesn't go to neutral every time the car stops if it has been started/stopped several times in a short amount of time/distance.
Some hybrids and engine stop/start systems are programmed like this: they will shut the engine down for the initial stop, but if you move ahead again (engine restart) only a short distance, it may not shut down again until you've gone above a certain speed threshold. Otherwise the feature may become annoying to the driver.
The neutral-to-start engagement of the Mirage CVT may be programmed the same way for the same reason.
I'm interested in seeing this feature first hand.
View my fuel log 2014 Mirage base ES 1.2 manual: 54.0 mpg (US) ... 23.0 km/L ... 4.4 L/100 km ... 64.9 mpg (Imp)