He spoke to specific engineers who were personally involved in setting up the most commonly used Neumann lathe. There was complete agreement among them. When I was a kid in the 50s, my parents had a H-K receiver that offered a choice of 2 or 3 equalization curves, plus RIAA. But that was all mono. Fremer does intimate that the conversation to stereo brought in the particular Neumann that was standardized to RIAA. It’s certainly logical that a mono LP might benefit from some esoteric equalization curve. Also, there’s no accounting for listener taste. If you get a charge out of playing with equalization, the PH1000 is certainly a way to be able to do it.