Kayn needs to transform faster in Rotating Game Modes

When playing Kayn in ARAM, Ascension, or most other RGMs, his champion damage meter needs to fill faster, and the cooldown on the opposite form achieved first needs to have a lower cooldown.

Kayn is severely underwhelming in game modes other than SR or TT, and that especially hurts considering that these matches tend to last much less longer. How would we play Kayn on Nexus Siege as he is right now? Just like we have quick-charge items in these modes, and Gangplank automatically gains tokens during ARAM and RMGs, Kayn needs a fine tune in order to be a good pick in these modes.

EDIT: With the discussions that have arisen in this thread, I'd like to also point out that in certain modes such as ARAM and Ascension your ability to recall is removed, making it even harder to transform in the first place. It's even more of a burden if you want to transform into the form that was placed on cooldown since the only way to return to the platform is to die, and it may not be up when you really want or need it to be.

For example, you're playing Ascension and the timer has 45 seconds left, but you just revived. Do you wait another 45 seconds and let your team 4v5 or head back into the fray not knowing when you'll be on the platform again?