Empirical evidence for whom? I have verified it for myself. You can do the same, but you have not done the process of emptying yourself of concept, yet you claim I am speaking of something mystical like unicorns. I am not speaking of anything, because words or things or concepts are not it. I am pointing to what is always there and cannot be described or experienced.
It's like you're asking me to use words to make you physically taste a food you have never heard of or tried. Same as how describing a food does not make you taste it. There is nothing to find, look for, whatever. It is far from mystical. But I cannot describe it because it is " underneath" description.
If you want to falsify it or verify it, empty your mind of concept and sensation, yet be awake. It is more real than anything. It always there, inescapable. It makes you "you" through every physical, emotional, sensational change. You cannot prove it or find it because it's already there.