Setup still is quite a bit a matter of taste. For example (some imaginary numbers):
With WR setup the owner has driven 2:00 laptime,you take it and drive 2:02
With setup B the owner has driven 2:02 laptime,you take it and drive same 2:02
With setup C the owner has driven 2:04,you take it and drive 2:01.
Which setup is better? Correct answer: the one you are the fastest!