Explosive Spear should recommend Compressed Duration instead of Prolonged Duration

In the Explosive Spear support page it lists Prolonged Duration [30% More Skill Duration] when it probably should list Compressed Duration [30% Less SKill Duration] as the skill does not benefit at all from additive skill duration but instead is much more effective when its skill duration is shortened.

You want faster detonation, not shorter duration. I think duration probably affects the flame ground which is why they recommend it.