Not exactly. There isn't one specific scan that states this outright; rather, the conclusion comes from a collection of many.
For instance, the scan involving Arjuna describes the INS as the rift that separates worlds, specifically depicted also as the gap separating heaven and earth. Not only does real numbers emerges from imaginary ones, it also envelops all material worlds. Furthermore, INS is defined as the boundary between material reality and the inaccessible inner sea.
This concept is directly linked to Avalon, which is itself an unreachable utopia, closed off and inaccessible without the emancipation from all physical properties. It is the mental space of the planet where its soul resides.
To expand on this, Avalon/Inner sea is presented as mental projections of the planet itself, often equated to it's Reality Marbles.
Ultimately the boundary (INS) can't be claimed as Avalon(it isn't described as a null domain), it can't be either a material world (it is inaccessible to physical beings and beyond the INS which acts as boundary ) effectively showing an Independence and superiority on both
I still need to organize and publish this arguments more formally, but anyway you have an overview.