I have to say I find your writings in this article very dishonest when I have pointed out several of the misconceptions you have about the Tokuriki and Tawfik papers you reference.
Purifying selection is what makes it possible for a protein to accumulate mutations without losing structural integrity. They even show this in the very papers you reference and I linked the graph in my post. You haven’t understood the paper you are relying on.
I suppose it is possible just you didn’t see my response.