Color blindness - Deuteranopia-type proof uses the incorrect Deuteranope confusion point.
The Deuteranope confusion point was published as xy = (1.08, -0.08) in color vision texts circa 1970.
However, the currently accepted Deuteranope confusion point is xy = (1.40, -0.40).
Unfortunately, Adobe Illustrator appears to use the OLD confusion point in the Color blindness - Deuteranopia-type proof mode. As a result, the simulation is inaccurate and inconsistent with current vision science understanding.
This may affect other Adobe products as well but I have not checked those. A comprehensive check should be performed to ensure the Deuteranopic confusion point is updated to the modern standard, xy = (1.40, -0.40) everywhere.
The attached document demonstrates the problem.