Namo Buddhaya!
I’ve talked about this before.
Nibbana in most general sense means removal of taints. Therefore arahantship is the end result and the foremost release that a human can experience in the here & now rather than sannavedaniyanirodha which is a means to an end.
The unmade is strictly speaking not experienced by anyone because it’s not a place that people go to and it is not included among things experienced through the allness of the all
Sannavedaniyanirodha is a cessation of all mental activity for one who attains it. Seeing this with discernment removes taints and one comes to, analogically speaking, know & see the unmade.
The difference between arriving at nirodhasamapatti and parinibbana is in the extinguisment of life-force & faculties but these things are not something that somehow colour one’ apprehension of the unconstructed. Rather the terms life force & faculties are delineated to explain the differences between the various dhammas and these things all end at parinibbana where ends the narrative about words like ‘knowing’ and ‘discernment’ and ‘bhava’.
Therefore we don’t say that parinibbana is enetered into but we do say samadhi based on the asankhatadhatu or the nibbananirodhadhatu is entered into & emerged from.
Whilst a person is in samadhi in dependence on the nirodhaprincipal we can talk about his life force, his bhava & discernment, but at parinibbana all these things end, the narrative ends completely whereas sannavedaniyanirodha is not without a narrative.