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.
That's not the kind of restriction that stops pool mining. The trick is to enable the pool members to steal the blocks they discover. Andrew Miller, a grad student at UMD, has an ingenious scheme for doing this. I am pretty sure I put the link in the article, under the first bullet in the "What to Do Now" section.
Wouldn't pool participants that use this extension to steal rewards be exposed to the pool simply due to their work being consistently challenged and thus lost?
i.e: The pool would notice that certain participants contributions are conflicting with other discoveries, and ban such participants?
Fees cost almost nothing to hostile miners. With a 20% fee, they get 100% of their hashrate through the theft, and 80% from the pool. So long as you pay anything at all to new miners doing this attack is beneficial.
That wouldn't work either. Even if to make it so every 3 blocks can be rewarded to an address (let's say), then you can simply write your own wallet that will use randomized addresses and simply forward their reward to the pool's wallet, which then distributes to the "real wallets".
The only way you can truly prevent pools from taking over is create a system of authentication that'll destroy anonymity.
Let's say you implement a restriction like "5 blocks in a row max for a given pool". GHash can split into GhashA and GhashB, and keep going.