The Blight Serum addon would be much more fun if it was bound to the secondary power key

I'm trying this addon on every killer I'm leveling up and so far I came to the conclusion that having it replace the main ability makes it unusable on most of them. It's a pity since it's a fun addon and the game needs more of them... imo if it was bound to the secondary ability it could work better on most of those "problematic" killers.