Duo Boosting Question / Feedback Request

I'm aware that duoing with a friend is 100% legal. I'm also aware that duoing with a smurf is also legal. This is not about anything involving those two items.

If somebody is MMR boosting an account (i.e. either via a friend logging into the account or via a"boosting service"), and you knowingly duo queue with that person, is that legal? I don't think it should be but I didn't see anything in particular prohibiting it.

I think it's stupid as you're being put in an elo you don't belong in. However, I'm seeing a lot of it again now that the season is ending and people want ranked rewards. I'm seeing 100+ match bronze accounts with recent ranked matches suddenly win 25 games in a row with different champs and carrying every match. And many times these people duo with another another account until they hit the bottom of a tier (usually gold), then they duo with another account until that hits the bottom of the next tier. And so on and so on until the account no longer wins the overwhelming majority of matches....then it stops playing entirely (or goes on a losing streak with the prior champions).

While I know the booster should be punished (and I do report these via support tickets), what about the people knowingly duoing with the booster? I think they should have the same punishment.

NOTE: Again, this does NOT refer to duoing with legitimate smurf accounts. These are accounts that either are being played by a booster or intentionally lower elo than the player should be.