[Pyrana Prime: You got this cool buff, but you're not allowed to use it]

This post aged like sour milk. As someone coming here in 2021 to look for a possible way to extend its duration: the problem hasn't changed on that. Also that being said it is currently one of the most powerful sidearms in the game (at least as a prime since the kuva nukor outshines it in every way imaginable) but it still holds up very well in end-game content. So to anyone like me looking for a way to extend its duration in 2021, don't bother. You can't. But that doesn't make the gun a gimmick. Its still very friggin strong.