Last Hitting Minion Gauntlet

Greetings fellow summoners!

Seeing how much of an impact that minions make in our games, I've desired a way to practice my abilities with last hitting without the influence of other team mates. My desire for this has spurred an idea to have a sort of single player mode, if you will, where you can jump into a shurima themed lane, similar to howling abyss, where its just an endless flow of minions to practice being able to freeze the lane, push the lane, or just practice your abilities to last hit with different champions.

With the recent introduction of Intro level bots, I can see this mode having 3 difficulties. Intro level where its just the minions to work with to practice the above. Beginner level where you have the regular minions, like intro, but with the addition of having random skill shots such as nidalee spears, ezreal shots, elise webs, etc come shooting out of the side of the map at random intervals for the player to try to dodge while practicing last hitting. Lastly, Intermediate level where in addition to all of the above, every minute or two minutes, a cross map ult comes down the lane from varying angles for the player to dodge, such as a lux laser, a jinx rocket, an ashe arrow, etc.

So what would be the point of playing a mode such as this? Well, you can practice mechanics in a sort of sandbox, but perhaps there can be leaderboards for the summoners to compete for who can survive the longest and the highest number of cs in a matter of 20 minutes, or compare it on a champion to champion level as some of us know how difficult it is to last hit with morgana!

I'd love to hear any suggestions or perhaps some criticism on how the this mode could be flawed!