So, it is working, displacement is there. Last time I forgot to assign a texture to modifier.
But inicialization process was really long and scene while rendering takes 227GB of RAM. When this will be fixed, I think it will be awesome 
it was standard render not IPR so good thing was that unloading RAM was very fast.
As I said, I’ve already logged the issue. Will inform you when the devs have time to assess it.
I know. Thank you for your support.
Hi,
We just released Forest Pack 9.4.2, which fixes the excesive memory usage with IP and Camera clipping/falloff.
Now, IPR works great, thank you. I have to disable dispacement.
So now displacement fix and it will be great 
Anything new about the displacement clones problem?
No news; I doubt it is something trivial to solve.