Dwelling Upon Seeming Levels of Emptiness?
Impermanence is unsatisfactory. Chasing impermanence leads to suffering. What then should be known as known?
To this point, the Venerable Sariputta teaches:

DN34:1.3.23: What two things should be produced?
DN34:1.3.24: Two knowledges:
DN34:1.3.25: knowledge of ending, and knowledge of non-arising.
DN34:1.3.27: What two things should be directly known?
DN34:1.3.28: Two elements:
DN34:1.3.29: the conditioned element and the unconditioned element.

The conditioned and unconditioned elements are known by their characteristics:

AN3.47:0.3: 47. Characteristics of the Conditioned
AN3.47:1.1: “Mendicants, conditioned phenomena have these three characteristics.
AN3.47:1.2: What three?
AN3.47:1.3: Arising is evident, vanishing is evident, and change while persisting is evident.
AN3.47:1.4: These are the three characteristics of conditioned phenomena.”
AN3.47:2.0: Characteristics of the Unconditioned
AN3.47:2.1: “Unconditioned phenomena have these three characteristics.
AN3.47:2.2: What three?
AN3.47:2.3: No arising is evident, no vanishing is evident, and no change while persisting is evident.
AN3.47:2.4: These are the three characteristics of unconditioned phenomena.”

These characteristics guide the knowing.
Knowing is informed by perception. Perceiving the form of a cup, one perceives simultaneously the emptiness within. They are one and the same. By relinquishing form, emptiness necessarily grows as described in MN121:

MN121:12.5: There is only this that is not emptiness, namely that associated with the six sense fields dependent on this body and conditioned by life.’
MN121:12.6: And so they regard it as empty of what is not there, but as to what remains they understand that it is present.
MN121:12.7: That’s how emptiness is born in them—genuine, undistorted, and pure.
MN121:13.1: Whatever ascetics and brahmins enter and remain in the pure, ultimate, supreme emptiness—whether in the past, future, or present—all of them enter and remain in this same pure, ultimate, supreme emptiness.