Advanced Training Mode?

Hello everyone I am fairly new to league of legends, but I have a lot of experience in competitive gaming from quake to tf2, I have realized something that is missing from league that could help a lot of players and possibly teams. My brother introduced me to a video showing off some very advanced in league of legends terms mechanics of the champion, I wanted to practice the things I saw in the video but realized when I go into a custom game I have to play out and farm like I would a normal game. Does anyone know if a feature with advanced training has been discussed by riot? By advanced I mean being able to go into the game, and change any value I wish for the sake of practice, no cd on skills, max cdr with no items, etc. I feel like too many people troll in normal games doing things like this and feel like it could help improve league from a lot of perspectives. Sorry for the long post, to sum it up has this been discussed before and or does it exist and I just am unable to find it?