Robert Olislagers, Centennial Airport Executive Director, informed Centennial Airport Community Noise Roundtable (CACNR) members of the Congressionally-mandated noise studies required of the FAA, pursuant to the FAA Reauthorization Act of 2018, Sections 188 and 173 regarding alternative noise metrics.
As he indicated, it is a good primer but offers nothing in the way of alternatives.
The second link is a commentary from Steve Taber, FAA attorney/advisor; Director Olislagers wholeheartedly agrees with his assessment.