Updated January 7, 2023

Photo © Alexius Jorgensen.
The Enlightenment of that which is One is not about seeing tunnels of light or something else because it takes more than one to recognise something. It is about not being conscious at all.
Consciousness is a fabrication of the brain meant to keep you aware of being someone who experiences something, although all experiences are nothing twisted into something.
This includes the brain, or something else doing it, you being someone and something being aware of this, because it takes more than one to be or do something, and there is no more than that which is One since it is formless, thus endless.
Read about the Enlightenment of that which is One in HACK #6,
The inward-facing senses, Enlightenment and glimpses of it.
Read about the fabrication of the self in hack #4.1 The basic self versus the special one, and the bliss of not being aware of it in Where to find the bliss of the empty breath.