Idea to Help Curb Mobility Creep

With the release of Kalista, it has become clear to many how prevalent the mobility creep in League is. (Although there is a large group that has been feeling it for a while) Another problem with the current state of league is the lack of variation in summoner spells, with half of the summoner spells being chocked out by the dominate spell: flash. Now, why should a champion that is hyper-mobile such as Kalista be able to flash as frequently as somone with no built-in mobility such as Ashe? My proposition? Change the base cooldown of flash (even availability) depending on what champion is running it.

Summary: vary flash cooldowns based on the mobility of the champion taking it.

I know that there is a typo in the poll. It won't let me edit it!