One of the next pieces of work for us as a community to do will be to negotiate / lobby for new regulations that are appropriate for these craft. Every state in every country has different rules concerning registration, licensing, and safety equipment. Most of the rules are created for boats and large, heavy, noisy jetskis. Jetskis are banned in a lot of places in Australia - mainly because they are noisy and dangerous, considering they weigh 500kg and can travel over 100kph. Where an eFoil really has no more impact on the environment or other water users than a foiling kiteboard or sailboard. Infact a foiling kiteboard is faster - as it is lighter, has more power and less drag.
Regarding safety equipment I think a leash is a very bad idea. It could be caught in the propellor and even if not it could cause the board or foil to hit the rider in a big crash. Exactly why I have not worn a leash kitesurfing since I got hit in the head by an elastic powered kiteboard 20 years ago.
I do believe riders should need to keep a safe distance from other water users and not use efoils in surf breaks with other water users. And perhaps carry safety equipment similar to other powered craft if travelling more than say 500m from shore.
It will be an interesting few years to see how things in this space develop. We need to work together on this so we don’t end up banned - like Segways are in Australia unless on private property.