Yeah i am doing that when i have time and that is helpful too. However on AI test my hero will set to face a random enemy with unknown stats and also an AI. In this way, you can see how AI behaves.
Similarly, battle arena replay also do that in an enhanced way. First, the replay shows battle between player controled hero versus AI hero which is not possible in AI test. Additionally, I intended to suggest battle replay to see how other players counter my builds so that i can further improve or change my equipment base on what my hero lacked.
Hope you understand my point.