Kalista oathsworn

So in my last game I made a stupid mistake, in which I forgot to oathsworn my support in the first 3 minutes. After that, you can't switch oathsworn anymore, so you can neither do your first oathsworn on your support. So in my whole game my W (except of the spooky ghost wards) has been useless and the ultimate acted weird too. Like it did pull the support towards me, but the support couldn't go anywhere from that and kept on sticking to me for an amount of time.

I was wondering if this could perhaps be changed because I think I'm not the only one that forgets this sometimes. So perhaps change it from 3 minutes, to 10 minutes? Then you're still not in the group fights yet (unless one champ got super fed and rockes the game) and then you're already in the game so you'll sure notice that the oathsworn is missing and so you can do it in time...

p.s. if this is placed in the wrong board, please tell me.