Idea for Phase Rush: Allow You to Ignore the Movement Speed Limiters For It's Duration

For those that don't know, there are currently set soft and less soft caps on movement speed. I think it would make Phase Rush a lot more attractive if you were allowed to ignore the movement speed soft caps for the duration, similar to how the attack speed Keystones let you ignore the attack speed cap. It would allow for some funny play styles without making those who initiate with big movement speed bursts (like Heca) too OP. What do you guys think?