[Suggestion] Training grounds queue

Hello everybody, and especially Riot guys.

First a word of introduction. I'm a diamond player and one trick pony who's gotten there by playing almost exclusively a single champion. Obviously, whenever I'm pushed to play anything other than my main I fail to cope with the skill level and most often make my team loose the game. However, I can play those other champions on normals and pretty much carry, mainly due to my decision-making being superior to people playing there. Hence, the only way for me to learn new champions (apart from online resources such as guides) is to play them on ranked where I'm able to perceive my mistakes as I'm getting punished for them. This however would result in me drastically loosing elo and makes me stick to my main. I think there are a lot of people with a similar problem.

Therefore, wouldn't it be a good idea if there was a 'training grounds' queue set up where people could play with others near their elo - similarly to the current ranked queue - with the only difference of not falling nor climbing the actual ladder. I realize the level would be slightly lower there since everybody would be just queuing to try new stuff but it still would be much better than normals.

Discuss! ^^