Kalista in game clarity issues?

Kalista has always been one of my fav champs since she has come out. Her unique play style is so different from every other champion and she really brings a lot to the team.

One issue I've been having with her is that I often misjudge when my e will kill a unit. This often messes up my laning phase because I depend on my e to get majority of my farm and often I totally mess up team fights because I thought my e would kill a unit but instead it just goes on cd

Would it be too op if there was a little indication that your e would execute a target (much like cho gath ult or garen ult)? Maybe riot thinks it would be too strong if she could see if it would kill a target, maybe part of her intended play style is to choose between using the e or to risk sending another spear into them. I'm interested to see what you guys think and if it would be too strong if she could see what target would die

Also I'd love to see maybe a counter of how many spears you rip from them after you use the e. It'd be pretty satisfying