In the current format of how they are implemented. A lot of the time they are active is waste by loading times or disconnects or waiting for other players.
So why not make them active for a set amount of matches. Ie they last 15 games. That way no matter how long you are waiting in the loading screen you’re not wasting the xp booster. Bonus it is also away of stopping people quitting matches. You could implement a 5 game forfeit to their current or next booster as away of incentivising to finish games.