Well there's this thing called ignore and it's great, I love it. I love it so much that I have forgotten who I ignored. Well when going into a ranked game sometimes that guy is on my team and I don't have a clue he's talking during team picks. What I'm getting at is, there is nothing that shows he is on ignore and there are no options for me to unignore him during this time. I suggest you install a feature during team picks that shows people muted and an option to unmute during this time. Yes I probably will go back to ignoring him, once a rager always a rager but at least I can give him a second chance and hope for the best.
Please consider this.
Also please consider installing voice chat with muting options. It would help with coordination in solo que and maybe have less ragers (I realize people will just verbally rage out loud but at least some of us can communicate.)