jenkm

If blend color Luminosity > 50% then: All pixels with Luminosity values less 50% are replaced by the blend color, and the pixels with Luminosity greater 50% are replaced by inverted blend color. If blend color Luminosity < 50% then opposite: All pixels with Luminosity values less 50% are replaced by the inverted blend color, and the pixels with Luminosity greater 50% are replaced by blend color. So this Contrast Negate mode is some kind of two-tone Posterization.

Yes, like Linear Burn, Divide mode was also lost.

We can invert the layer and apply the Subtract mode to achieve exactly the same result as Linear Burn. But this is not the way for brushes, layer effects, etc. Besides, PSD files containing Linear Burn mode not imported correctly. This the standard mode, which is present in all other graphics programs and used in the books and tutorials, should be added to the Affinity.