User blog comment:Mineko Charat Lucky/I propose that Flash should really be reworked/@comment-1330314-20130809194141

That's a nice thought, but ultimately it would just cause everyone to pick Yordle Stompers over all others, simply because Flash is that good. Shifting the "small steps" passive onto Flash itself could help, though the effect as you've designed it would also cause balance problems. As has been said below, some champions may have on-demand stuns, but they're fairly small. Implementing an effect like this would cripple, for example, whereas would be far less affected despite having a much better gapcloser. Having the cooldown increase by an amount proportionate to the distance travelled with each ability (for example changing the effect to "flashes, blinks, leaps and dashes increase Flash's cooldown by 0.03 times the distance travelled" would have increase the cooldown by 9 seconds each time and  increase it by 14 seconds. Overall, Vayne would still take the harder hit, but that would compensate for the on-demand nature of her dash.