In terms of AI matches, there could be a Kill% and Tower% (Get a hero kill and a tower destruction, respectively), and in terms of practice matches, there could be a Steel% (Kill steel).
These former 2 would be easier to grind and all 3 could provide some variety.
Just some ideas, thoughts are welcome!
Just first to kill a hero wouldnt be too fun imo. Mainly because any ranged character can probably just stand around a corner just after spawn and steelAI can't respond.
That being said might be fun to have a experimental category where we can have any random speedrun category. That we may just want to experiment with. Which would entertain the idea of learning for the main categories. In that experimental category 1 of the levels could be "kill offlane any%" or "final evo crest any%" similar "light" or "experimental" runs. As it would be a fantastic way to learn ai habits and better oneselves at the game.
We can probably ask int to make another level category for the experimental runs such as the ones you suggest. If any sticks we can make that specific one as a seperate category run.
How does that sound?