All you would have to do is update the design by using a piston instead of the sign, then place a block so it can only grow to a maximum of two blocks. Then you have a mostly functioning random, but the only problem is it takes awhile for it to grow back, this might be able to be solved if after a cactus has sent out an output, it shuts off for the time it would need to grow back, and at the same time forwarding the circuit to another cactus.
Still some minor flaws but it defiantly proves that he is not a retard, his concept is able to be as working as any of the other ones, even if it increases the complexity.
Uhh and he didnt invent it? It is etho's
I know, that doesn't affect anything.