I think the source of the confusion is that I'm carving off a stricter, and smaller, definition of the word "spec" than what we're used to. I agree. The word is not quite right.
In general the answer to your questions is "yes and no." Well, really it's no - except that as a fairly common case, for example when we want to catch compiler errors without breaking out of the system, we virtualize Nock within itself. This is also serviceable when it comes to adding an extra operator, 11, that dereferences the global namespace. But the fact that "virtual Nock" is just a virtualization stack within one Nock interpreter is not semantically detectable.