Stop letting duos queue up for ranked
I can't even believe the amount of crossplay duos that queue up for ranked. The issue is that they are frequently not very good, or at least one of them is ok (at the rank) and the other isn't. Because the game plays on the highest rank, you are essentially dragging a lower skill player and griefing the random third's game. They are also usually comming in private to each other, excluding the third - and they are often belligerent to the third when any communication is attempted because they outnumber them.
The RP loss I've incurred duo to bad duos is incalculable. INCALCUABLE.
No legitimate reason to allow a duo to queue up for a ranked game. They can play duos. Three stacks or all randoms. In fact - even better would be separate modes for randoms only.