I know many don't use this skill, but it's broken. If you cast it multiple times, or any time before the buff times out, the timer does not reset. It picks up where the previous counter left off.
E.g. I cast forward momentum, wait 4 seconds and cast it again. The new timer is for only the remaining 4 seconds. This poses a problem when I'm refreshing this buff, and cast it one second early. I have always been thrown off by this buggy skill, but I want to use it.