Giovanni
I asked myself the same question. The facts say that setup is based on race start conditions and depending on how wrong is your setup, you will receive an handicap. Here ends setup role.
It would make sense having a setup considering the whole race length but my 180+ racing experience says what I wrote above.
I would disagree. In my humble opinion, “ideal setup” sets the fastest laptimes and ideal setup is tied to the current weather condition on track.
So if a race starts dry, everyone but you on dry setup, it starts raining, I think you on wet setup will be at an advantage as long as it actually rains.
When drying, you’ll be at a disadvantage cause it’s considered dry (not raining means dry setup is ideal)
This is what my race experience tells me but I could be wrong here