Ideas for Training Mode

Riot has implemented a training mode into the game. A feature I could suggest for that is making all champions available rather than just the ones we own. So that we could test out champions to see which ones we like and/or dislike. I am currently struggling to find champions that I am very skilled with and enjoy playing. I do have champions I like but I just haven't found the one. I could farm up all of the IP to buy every champion and spend hours playing and refining each to see which ones I like/dislike but it would be much simpler if there was a way to test any champion I want in a 1v1 training grounds or even more players so that you could think about how champions work together with teams, and test out support champions. Thank you.