Good work so far,
Going from last ride's expirience, we need to set some soft rules, no big deal, but the inevitables may happen and that is niggling breakdowns.
Chains fall off,clutch cables, etc things like that, the unexpected.
It's best we all stop and check out the rider and their problem and we fix it.
This is what it's all about, endurance, fault finding and solutions on the spot as they occur.
If it's unfixable, I guess have enough tools so one can remove chain and ya on ya own form there to pedal back, ultimately if all else fails or towing a bike can be considred to if the terrain is a hassle to pedal till ya on the flats again.
Fuel.
Depends what run is planned,how far and all that. But we had to re-fuel half way and it got messy with oil mixing, each had their own specific mix and to me it's 6 one way, half a doz the other. But let's decide now how we gonna do the fuel mix if this is a long run.
Other than that, not much else I can think of except food and coffee.