"So again, Kotlikoff proves us right: "
Not by the hair on your chinny-chin-chin ... Nor is he "eschewing" anything. You'll notice he says "IF" in the small bit you choose to quote and in addition he also says:
"We assume that the monetary authorities do not accommodate the adoption of the FairTax, which is to say that they restrain the growth of the money supply sufficiently to prevent market prices from rising. As mentioned, this is merely a simplifying assumption. We could just as well have allowed for monetary accommodation, so that there would be no fall in producer prices under the FairTax. Doing so, however, would merely have made the algebra more complicated without changing the results."
In no way is that an "eschewing" anything.
Maybe I am missing something, but that seems to be the identical assumption that Jorgenson made, except Jorgenson assumed after tax prices would stay the same due to lowering wages, and Kotlikoff assumed that he would keep after tax prices constant by monetary policy (which I suppose in the long run could force wages down, but again is a unrealistic assumption). In the short run that kind of monetary policy would destroy the economy before the wage-issue was rung out.