Tryndamere ult change idea

Nobody enjoys fighting a Tryndamere with that 5 seconds of fun ult he has. I made this comment on a YouTube video earlier but wanted some more feedback. What if Tryndamere's ult length was relative to the fullness of his rage bar. If he has a full rage bar he gets granted the full 5 seconds, but if he has a less than full bar he gets a prorated length of time. (1/2 bar = 3.5 seconds, no bar = 2 seconds minimum). This gives teams a little wriggle room when deciding how to deal with him without taking too much away from his strong dualing power.

Assuming he's in lane or a teamfight, odds are he'll have a healthy rage bar right? Great, he gets the full 5 seconds and gets to wreck faces. But, you catch him in the jungle or in rotation after his rage bar starts depleting you can take him. Catching him in a bush gank allows you to burst him down to almost dead (if not outright kill him, in which case his ult probably won't even be cast) and he ults for a shorter duration allowing you chase for 2 seconds to get the kill, or for him to use those 2 seconds to spin over a wall to safety.

It'll cause Trynd split pushers to have proper ward coverage so they're not caught out on their way to start splitting and make them think twice about how/when they fight instead of running headlong and constantly ulting away, never to die. He would still gain the extra Rage his ult provides so he'll have the extra crit chance if he chooses to fight, but his ult length would be dependent upon his current rage when R is pressed.

Whatcha think?