Another angle: The planning and flight schedule of the whole race.
How did this work before? Did pilots just jump in to take the baton when it was available? Did they pick a new destination on their own?
Or was this coordinated somehow?

If interested pilots provide their free hours then they can all be slotted in when it suits them.
If you know beforehand when you have to fly then you can plan your real life around it.
This also helps keep people with little time on board. If pilot X only has a few, very specific hours then these can be reserved for him so that he will not lose his opportunity because pilot Y, who has seas of time, takes the baton during these hours.
We may also help inexperienced, daylight-only pilots by giving them daylight legs.

If the route is planned centrally then pilots can be given a simple task: Fly from A to B, no need to worry about which airport to pick as B.

Experienced can help others planning their flight, decide how much fuel to carry, at which altitude to fly.