Also, the OFB (Official Fighting Battles) draw is completely random from the first round. If you're constantly talking about the rating, then at least make the draw for the first two rounds based on rating. And then allow the person with the highest rating to participate in the OFB. In the OFB, withdrawals are very decisive; don't come up with nonsense. Sometimes, a withdrawal decides everything for the top spots in the final rounds, but if your opponents withdraw, you practically have no chance.
Currently, the FB (Fighting Battles) also doesn't attract enough strong players due to the quota. And regarding the system, you could create 4 groups (16 players) that are balanced based on the same rating and their achievements. 8 players advance, and then, as always, a double-elimination bracket follows. That's where you can have best-of-3 and best-of-5 matches, etc.