Possible MF Buff?

So, I am a Miss Fortune main. Miss Fortune has great all-in and poke throughout the game of League, yet I think Miss Fortune's mobility could be better. I mean, don't get me wrong. About 100 additional ms from her W is amazing, but that additional speed is negated if she takes in any damage, even a single minion auto. Without that speed, she has like no mobility. All I ask, is that Riot does something cool with her W. Such as this:

When her W is activated it brings her ms back but it CANNOT be removed the entire time while the active part of her W is, well, active. Mainly, just make it to where the ms cannot fall off while her W is active. Or, they could just make her ms immune to minion damage.