Either Ban Leavers Faster, or Group by DC Rate

Comp Leaver/Sabotage Penalty : These will be the same across the board.

First Offense : 1 hour Comp suspension, 50 SR deduction and a warning to refrain from abandoning or sabotaging Comp matches.
If you leave or sabotage another Competitive match within 12 hours of your first offense ending you will receive a second offense.

Second Offense : 5 hour Competitive suspension, 100 SR deducted.
*If you leave or sabotage ANOTHER match within 48 hours of your Second Offense ending you will get another warning to stop abandoning Comp matches followed by your third offense.

Third Offense : 48 hour Comp suspension, Full rank downgrade and a final warning to not abandon any more Comp matches.
If you leave or sabotage ANOTHER Comp match with 24 hours of coming off your third offense punishment, you will receive the “Final Straw” punishment.

Final Straw: Full Comp season ban and a full rank downgrade.

If you can MANAGE to go the

That will not PREVENT Leavers, but it will certanly make people think twice about sabotaging matches.