"difference on lp/mm per image part" makes no sense in relation to your question about contrast change.
A lens may resolve more line pairs in the center than the edge, but a developer is not going to fix that.
Your original question as phrased seemed to be more about things like the Einstein / Marilyn picture combination. A high acutance developer enhances edges (high spatial frequency) but it doesn't actually make it sharper, only apparently sharper.
Digitally you can make an image have low overall contrast and high microcontrast or vice versa.
My main interest is to change MTF curve of a negative. If I am not wrong , MTF curve documents low to high lp/mm of image and its contrast.
Is it possible to change low and high lp/mm high contrast , middle lp/mm to lower contrast like Leica lenses.
Thats why a nude woman at night looks whiter , her hairs glow but her criss cross shirt seems lower contrast.
My main interest is to change MTF curve of a negative. If I am not wrong , MTF curve documents low to high lp/mm of image and its contrast.
Is it possible to change low and high lp/mm high contrast , middle lp/mm to lower contrast like Leica lenses.
Thats why a nude woman at night looks whiter , her hairs glow but her criss cross shirt seems lower contrast.
Here is included a discussion of developer effect on film MTF curve: http://www.normankoren.com/Tutorials/MTF1A.html
The adjacency effect in a dilute one shot developer is visible on the red line at low frequency.