I don't know why you're suggesting anything along those lines, it doesn't look like the author's link to a method to stop pool mining has anything to do with re

I don't know why you're suggesting anything along those lines, it doesn't look like the author's link to a method to stop pool mining has anything to do with restrictions like that. It seems instead the author links to a post about allowing arbitrary participants in a pool to steal the entirety of the mining reward. Thus, there would be no incentive for individuals to participate in a pool: whoever finds the solution could take the entirety of the reward. This kills the GHashA.