I am sure there is a thread about this. I have looked but can't find it.

I really think it should be possible to come in to the pits and change your setup without having to go back to lap one and start over again.

What are your thoughts on this as I just think is more realistic....

I am not sure that's more realistic. Changing all of your setup parameter in real life would take quite a while, so I don't think you should be able to pit and rejoin immediately without losing your laps.

You should be able to change certain things, tire pressure, ect. Just the easy, quick basic stuff that can be changed in RL.

It has been suggested before and the truth is that it's not realistic.

Although you can tweak some settings real-time with the F11 key and give (a lot) pit instructions for tyres, pressures, camber, fuel and wings by pressing F12.
Use the arrow keys to do that, or shift+ arrow keys.

But to change your whole setup in a pit stop is too much imo, so it's good as it is imho.

You should be able to BUT you should have to take the time hit for all the changes.

So in the end, unless you are a long way into a long race it will not be worth the time cost.

feature not needed