MMR and teambuilder?

So I have come to the rather painful conclusion that I simply do not have the time in my life to stay overly relevant in ranked and chase that challenger dream. It sucks, it hurts, but w/e adults have responsibilities. I do however want to continue to improve and drive forward in the game, even if that is just in casual formats. However to improve and drive forward, I need the level of my opponents to rise as my skill level does, and I am worried that if there is no MMR involved in teambuilder I will stagnate and cease to improve. So my question is this: Do you gain MMR from teambuilder matches? I have heard you gain it through blind pick, but lets be honest, if I'm going to be playing casual for funsies, I want to play the role I want, when I want.

There is a saying that goes "if you are the best in a room, then you are in the wrong room". I thirst for self improvement, stagnation is unacceptable for me.