> I think what pros (eg. pro cyclists) do is that they try to find the best of both worlds - they train a LOT in lower intensity zones so they get very good at fat burning without actually reaching keto, but they then supplement it with the right type and amount of carbs during races so that they don't lose sprint power. But this is only my theory, I have never been a pro, and never been close to these circles.

You couldn't be further from the truth, especially in a race scenario, not to mention a stage race or a grand tour. Professional (and most well versed) cyclist will pile on carbs in the days leading up to a race, eat a pile the morning of the race and then continue to eat and drink a massive quantity of carbs. It has everything with them being able to replenish what's lost during a race lasting several hours, it is not at all sprint specific. They'll easily aim at 100+ grams of carbs per hour.

I would consider myself a well versed and well trained amateur cyclist. Depending on length of training session and intensity of efforts, I'll aim for 50-100g/hr. In a race my goal is 80-100g/hr from the second the race starts. I've done well enough in multiple 6-9+ hour races and training sessions.