I would add that there are different strategies to achieve the same time. I compared this split time calculator with my BestBikeSplit plan (both 3hr target), and there was 10 minutes difference after 1 hour!
If you’re lightweight, the later hills won’t take so much of your energy, and you can take it easier on the flat earlier section.
Most(?) people would also be better served with a negative split. Hold yourself back in the first half and really push on in the second half when it’s easier to gauge how much you have in the legs.
There’s more time to be lost blowing up towards the end than there is to be gained blasting through the first 30km.
