If you want to eradicate boosting, then simply make it so only the highest rank is considered in any given party. So if a level 40, 25 and 11 go into matchmaking together, then it should only search in the range of 40 and not take into consideration those lower ranks whatsoever. If you are a lower rank and cannot keep up with those higher ranks, then don’t go into matchmaking with your level 40 or level 50 friend.
Simple as that