Who pays for FIA-approved racing fuel and refueling zones?

The biggest difference is that a charging truck has high investment cost and low running cost. While racing-fuel infrastructure is the opposite.

Anyway on second thought a "connecting box/case" (maybe including cooling) that can be used on public chargers might be the best solution even in like 2-3 years
Obviously in a rally the organizers will then close off some chargers to the public and designate them as charging zones.