I've just added the ability to re-seed the playoff bracket after each round, exactly like the NFL does (e.g., in a 6-team bracket, if a #6 upsets a #3 in the first round, the #6 team will play the #1 team in round 2 and the winner of #4 vs #5 will play the #2 team in round 2).  
 
To use it, select Re-Seed After Each Round from the Edit Playoff Schedule link.