hum, I´m not sure. may be with this car the changes in the setup have to be bigger to feel something, but they can help. for example, is not the same to drive with a 25% or 40% of power on the diferential. wath I see this days is with 25% of power, you lose a lot of par through the inner whell wich start to spin too fast. and, in consecuence, speed through the corner.
I´m agree with you when you said that a setup change creates a different response, but this change can help you and your drivestyle to be faster. always when I change the setup, I give myself time to get used to. i change a little bit how I turn, accelerate and ...
my big problema is that I come from grand Prix legends, where the setup changes can be feel, but not in the way of assetto, automobilista,.. in gpl you can do quite well, without touching tyre presure a lot, and in assetto when you change they, all the car handling changes.
I hope you can understand all.