The list of things that CAN be done about it is long.
The list of things that WILL be done about it is readily apparent: absolutely nothing.
This game has a 100% tolerance policy for players to run as many secondary accounts as they like, and while the developer claims that running one for the purposes of cheating the matchmaker is against the TOS agreement, I guarantee you that they have never once banned anyone for this because there is no way to prove culpability. The TOS threat is just empty posturing to make normal players feel as if the developer gives a rat's **bleep** about the abuses we suffer at the hands of hard stuck masters who get tired of sweating in their own lobbies and then start a secondary so they can "have some fun" riding their way through the ranks until they stall out again near the top. Rinse. Repeat.
Secondaries aren't just tolerated. They're condoned. They're expected. They're encouraged. It matters not to the player using one, or the developer who wags their finger at the player while winking on the side at the same time... it matters not to any of them what this does to the experience of other players. Anyone using a secondary is a cheater, and if the developer had any integrity they would either shut down these accounts or ban players who use them. No excuses. Not, "I need it for my little brother." Not, "I play ALGS and I don't always want to queue in public and have people know who I am." Not, "I stream rookie-to-predator runs and my subs love it." None of that garbage is a legit reason to pretend to be someone you're not. There is no legit reason to pretend to be someone you're not. It's a pox on this game. It's been a pox on every other game I've ever played. In fact, I've never played any game that wasn't ruined, sooner or later, by the players. Sometimes while the developer looks the other way and pretends no damage is being done. Or that the benefits outweigh the toxicity.