Please Riot make Gunblade active INSTANT cast!

I get baited by this item everytime, I press 1 to cast it and I think I cast it but nothing happened because you cannot use gunblade while doing another action. I don't know if it's intended or not but it's really really annoying to see that your target escaped with 100hp and you still have gunblade whereas you pressed the button to active it. They changed it at patch 6.9, before that we could cast it while doing another action.