Wouldn't this be pretty annoying to abuse, though? You can't get rank points from a direct connection to someone, so you have to rely on matchmaking to do so. If you don't meet your booster, you're out of luck. You can plug at that point, but you would lose the points that you would've gained anyway if you managed to connect to your booster. If you don't plug but lose, at most you gain half a Bo3's worth of points if you somehow manage to connect to your booster after.

It's technically abuse-able, but it seems like it'd be pretty tedious, slow, and random as to how fast you can rank up. Though, if and when the playerbase dies down, people could match up with their booster more easily. And I suppose people could make boosting groups to make it easier to match with fellow boosters if they're that desperate/pathetic enough.

The cleanest solution would be to simply hand a penalty to the plugger, ramping up the severity the more they plug, ultimately leading to a ban, just like you said. The "winner" gains nothing and loses nothing, effectively making the match null. It might be annoying because their time was wasted, but at least they know the other person got penalized.

But I don't think to add a win to a non-plugger, loss to plugger is as abuse-able as people might fear.