It turns out there was actually an old post about the turbonormalized STC supplement in the Analog Bonanza section, and I was able to remind myself of what the situation was. I've corrected the numbers in the table.
The RPM does actually make a surprising difference (8% reduction in cylinder displacements per minute, plus knock-on effects of the turbocharger not needing to work as hard thereby reducing backpressure, plus leaning for best power resulted in some 15% reduction in fuel flow)
Also it's easy to forget (myself included) that the cruise climb table is not showing us the fuel flow at the target altitude, but rather the time-average fuel flow from sea level to our target altitude. In other words, the 25,000 foot target altitude line will show a much higher average fuel flow than the 25,000 foot maximum continuous power table, because it also includes all the time we spent at less efficient altitudes while climbing to 25,000 feet.
