You've missed the point: Nirvana is an absolute, even though Buddhism says there are none.
Nirvana is NOT an absolute. It is not an essence or a thing, it is not like Atman or Brahman. It is a state of mind.
"Unconditioned" is an adjective, not a noun. An important distinction. There is no "the unconditioned".
In the suttas Nibbana is a mind free from ( not conditioned by ) craving, aversion and delusion, that is the standard definition. And in the suttas and the Dhammapada you will find the refrain "Sabbe dhamma anatta" which means all phenomena lack self-nature, including Nibbana. This is clear and definitive.
In Mahayana texts like the Heart Sutra, Nirvana is a mind illuminated by prajna.
You're right, Buddhism DOES say there are no absolutes, despite peoples' desperate attempts to smuggle one in and make Buddhism into a school of Hinduism.
I really wish you would stop misrepresenting Buddhism to suit your syncretic new-age agenda. Be honest and admit that you had a flirtation with Zen Buddhism and then converted to Choprism.