OP is asking about a high acutance developer, not all developers, in this case there is no reason comparing a soft developer as he citied Berry Thornton who is not know for using soft developers. But Retina Restoration is right, even when limiting recommendations to high acutance developers the results are pretty much subjective. Unlike contrast, film speed or grain,, acutance is very hard to objectively measure. Some text called acutance perceived sharpness.
Then I thought, is there an objective measurement of acutance?
It gets complicated as definitions have evolved over time and both objective and subjective characterizations of “sharpness” have sought to factor in more parameters.
Historically “acutance” was a measure of how steep the slope is between two densities. Think of a hard edge in a negative (how to expose a hard edge is a sub-topic). If you magnify that hard edge it is never a perfect “instantaneous” change. There is always a transition. The steeper the average slope of that transition, the greater the acutance.
The problem is that is not all there is to it when it comes to how sharp that boundary appears. That’s where contrast/edge effects come in. There is also granularity. These things mess with perceptions versus just a straight measure of traditional acutance (edge sharpness).