Is there a real need for the pit confirmation once we cross the pit entrance line?? For me know there isn't, also it can be a real pain in the butt if your in the first few pit boxes, on a couple of occasions now I've pitted to find I'm in the 1st box, and by the time I've either hit the confirmation or spotted my box it's to late, and it's cost be big time.
And it's easy to fix as well - leave the confirm button there in case you *do* want to make changes, but set the pit options as confirmed by default once you enter the pit lane.
The confirm button needs to stay, but you should be able to confirm your settings before you enter the pit lane.
As a newcomer I'm really amazed with the complexity of the pitstop menu! Yesterday was my first race with a mandatory pitstop: I'm glad I listen to the advice of setting up a preset! My stop went flawless, luckily I was near the end of the pits… My preset was to change 4 tyres only; during practice I tried to make a change, and add some fuel… That was so overcomplicated and not intuitive at all! I can't believe this has been done by someone that is actually racing, and using this… I won't talk about all the confirmations needed, you probably know better than me. But just the wording "risky", "safe", instead of being able to set a number of liters you need… I took the start with way too much fuel just because it seemed impossible to set a quick top off if needed! Yep, I should probably make more preset: it looks like any adjustment "on the fly" is way too risky.
You can choose how many litres you want to fill up as well. But yeah, easiest is to have a couple of pre sets, and set the ones most probably to use highest in the list. And also, if you do need to change any of them in a race, make sure to do that on a long straight a couple of laps before you go into the pit.
In fact it's pretty confusing to see "Pitstop Confirmed" in the pit menu while you're on the track, only for it to deselect itself again once you enter the pitlane. I mean...why? Several times I've just sat in the pit stall for a few seconds before I've realized I forgot to re-confirm the pitstop after entering pitlane. Plus, as @Gopher04 mentioned, it disadvantages people in the first few pit stalls as they have very little time to bother with a pit menu while they're busy entering the pit stall.
I agree that it should be automatic. it would be great that instead of a single pit request button, there was 3 for the top 3 pit presets. The pit menu would then be used for unusual circumstances like major damage. In which case the added few seconds would not likely lose or gain you much on the track.