This has been an issue of mine basically since I started playing VT2.
Normally the option gives a hero selection screen when you’re matched to a game where your hero is already used by another player. It’s a great feature. However this seems to work inconsistently, though likeliest to happen with the release of GK & Engi.
Even though I have the option enabled, the game sometimes doesn’t matchmake into other games where my hero is taken. And even worse, sometimes it doesn’t matchmake me into games where my hero IS available. Which is when I look at the lobby browser and see 20+ games in West EU with my character available. It makes me question if QP even works at all.