I think there are three things that BWF needs to change: 1. Service Fault This has got to change. It is controversial and very subjective. 2. Overruling Linesmen Hawkeye is too expensive for badminton. I hope TV replay is the best answer. 3. Mopping Up Umpire has too much discretion. Why not permit each player one request (per game) for mop up and/or towel down!
#2 is worth considering but of course the number of challenges should be limited. #1 is fine the way it is and #3 is nonsense. When there is fluid on the court it gets really slippery.