As I expect that these machines have zero ability to enter autorotation following a loss of power, I suggest that they be restricted to operating altitudes from which a safe power off landing is possible = remains in ground effect.
I believe that some jurisdictions already permit ground effect [only] vehicles to operate without aviation oversight. I presume that this would be practically over water more than land.
I am no expert, but the only one of these I know about has all rotors powered by individual motors and batteries, with redundancy for at least one failure.
The idea of "personal aviation for all" rears its head every few years with some weird and wonderful new machine built in someone's garage. These new machines may, just may, be the first step towards a realistic proposition (god help us!
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