Crashfrog, I submit the superluminal realm is substantiation of the spiritual and so-called supernatural realm.
Since that realm is not populated by ghosts, nor spirits, nor is capable of gifting humans with magic or paranormal powers, I submit that claim is
a priori ridiculous. You might just as coherently assert that
Cleveland is substantiation of the spirital realm.
So a realm beyond, faster than the speed of light, could by definition be called supernatural.
As a realm governed by physical law, and capable of being affected by and affecting the world of matter we're familiar with, that realm, by definition, is natural, not supernatural.
I am stating if it's real, it's part of reality, regardless of the term we call it.
If it's real, part of reality, and it's something we can detect, then it's part of the natural world, by definition.