Huh. When you say that "it's not very effective" do you mean the segmentation between the pools, or the actual anticheat isn't very good? (I'm assuming the latter - I've heard that VAC is pretty bad as far as anticheat goes)
Community alternative (faceit) requires kernel level access. The actual anticheat matchmaking is essentially unplayable
Oh sorry - I misread your suggestion! I thought you were talking about separate matchmaking logic for known cheaters, but you're asking about opt-in matchmaking for those willing to use invasive anticheat.
The example still kind of applies. In the CS world, serious players use Faceit for matchmaking, which requires you to install a kernel-level anticheat. This is basically what you're suggesting, but operated by a 3rd party.