4 minute lock out of the other form as Kayn is brutal

Why does it work like this? No matter how close you are to finishing the other form, it always gets put on a 4 minute coodown even if you attacked both melee and ranged equally. Also most of the time you will finish Rhaast first, which means Shadow Assassin form becomes useless as you cannot get it early when it is at it's strongest and you are delaying your powerspike.

I know it's for lore purposes and all that one defeats the other and what not, but I feel like it shouldn't affect gameplay to this extent. IMO it should be lessened to 2-3 minutes, or making it so attacking the champions for the other form still reduces CD.