HELP: How to randomize cycles displacement materials across particle system objects?

I am trying to use a particle system in Blender to create a field of objects (in this case bumpy rocks) with a procedural texture material on each object where each object has a randomized bumpy pattern (using cycles “true” displacement).
Based on feedback from another thread (and a discussion on Stack Exchange), I was able to get the Random output from the Object Info node to modify the way a procedural texture is mapped to a emitted object (which is extremely helpful). See below to see layout (where I display the procedural texture as a diffuse color rather than displacement):

As you can see in the image above, the procedural texture pattern appears different for each ball, which is awesome (or at least could be quite awesome if I made a better-looking procedural texture lol). However, if the exact same setup is used for displacement, the patterns are identical on each ball (in other words it doesn’t work).

Some feedback I’ve gotten would indicate that what I’m trying to do is currently impossible in Blender (shout out to @Secrop for being very helpful in this discussion) , but I am definitely all ears for workarounds (or better looking forward to hearing what I did wrong here that would make this work if rectified).

One workaround is to covert the particle system into a bunch of separate objects (though that does seem to be extremely slow and of course not as convenient).

Here is a link to download the file:

Thanks in advance!

You know what the problem is… but it’s possible to minimize in pratical terms.

For example, if your particle system is from a group of 100 or 200 different objects, you can use something like 10000 particles and still have a great diversity that fools the eye. I mean, 200 objects for cycles is not that much, and unless your public is somewhat autistic, most people won’t even notice that there are repetitions from a group of more than 100.

That’s a good work-around because I can have the colors and bump maps vary across all objects, but actually have the displacement vary across 10-25 objects. That breaks up the monotony. I didn’t know you could have particle system emit a random selection from a group of objects. That’s quite useful! Thanks Secrop!