Looking at both photos it's clear to see that you can mount the flap inside or outside the fender profile. Any particular reason to choose one or another?
Personally I did it because I got it to slot neatly inside the rolled edges inside the guards. I can see the merit in it being more flexible and easily accessible mounted on the outside though. With the wavy guards I probably couldn’t have managed that at all tbh
Can confirm the lazy/clever thing is 100% effective.