[gtsteve]

Some recent changes were made around people who frequently get blocked being auto-blocked for you when you join the game. They have highlighted red names like "Dalmatian" and "Flamingo", etc. If you un-block them, you swiftly find out why.

So, blocking communication is one thing you can do to help send a signal that this player is toxic. I guess eventually they start getting queued in lower trust factor lobbies but that's speculation.