Nice find! Unfortunately the proposed fix can still be exploited to a "time traveling attack". They seem to be working it out in that thread so I will keep my eyes on it.

Brother3, LOL - thanks for the find!
I made a suggestion to that thread for a new and simple algorithm that should remove the complexity and time travel issues of KGW and if we use it for CGA, it will quieten the jumps in the diff by averaging the block find time so that luck and sudden increases do not make it jump around.