This is a good read.
Some of it is Vray specific.https://www.cggallery.com/tutorials/displacement/
But the theory behind 32bit and positive and negative values is still relevant.
I belive you would not be able to replicate what he does on that webpage in Octane with a 32bit displacement.
The workaround is to use 16bit displacement instead, and to be fair, 16bit displacement is perfectly fine and is more flexible when it comes to modify the map itself.
BUT.... 32bit displacement is known to have more accuracy.
It would be nice to keep this talk going until we are on the same page.
Because it seems Paride still means we are suppose to be able to do this.
And i would love to be wrong about this !