Lang’s questions:
“So another way we can say anything about Nibbana is asankata dhatu. Short of parinibbana, is this what is “experienced” by someone in Nirodha samapatti?”
Yes. Nirodha samapatti means “without any citta”. Nothing about this “world” is experienced.
“And this asankata dhatu must be “one of a kind”. All other dhatu, the kind made out of the maha bhuta, are “sankata”, correct?”
Yes. Everything in ‘this world” is included in the six dhatu of pathavī dhātu, āpo dhātu, tejo dhātu, vāyo dhātu, ākāsa dhātu, viññāṇa dhātu.
– asankata dhatu is devoid of any of that.