Just wanted to know if this is a typo or actually intended to work this way? 

From what i gathered by testing how long this would take to unlock, it made no sense at all to me. The number of missions you would have to play to "naturally" unlock this is staggering and even if you artificially try to boost uses aka always use all charges, even if not needed, this takes a massive amount of time.

So whats the deal here?