this would be a custom movement system.
It would make sense to abuse knockback triggers for that. But in the end it is extremly hard to make it as smooth as it is now.
the biggest prob is the AI. You have to calculate how the unit have to move.Expect in the case that you map is flat, ot you are only talking about a map with only air units.
If you just want to make some kind of sprint ability, then just use a knockback.