I looked for a simpler solution by using the wire-, round edges-, native ao and so on shader masks & mixes. They do work, but as one would expect, the displacement has top priority.
C4D has an option to apply textures before or after displacement, but that's just for colors etc. Maybe some option/checkbox for AO to be applied before displacement would be helpful. I'm too tired to think of something more useful. Maybe make the displacement respect the order of the shaders/maps in a layer shader if one's used. Everything optional of course.
Otherwise, well you can do it manually but in my opinion, that's not very elegant.
You could bake out an AO map or the gradient shader (2D Box mode)and use it as a mask for the displacement but, I'd rather go with vertex maps and just insert some poly loops or a tiny bevel if the face count is to low. Adjusting these poly modifications is simple.
Anyway, who would want an infinitely sharp corner? that's just unrealistic but incredibly dangerous! Imagine someone wanting to go around the corner but being distracted by their mobile phone, the person turns around too early and abracadabra, you have a two cadavra people who are alive and well, like Jørgenson. However, having split into two people, as Riker did in TNG with the transporter malfunction, would create a bureaucratic hellfire.
