EBTs are very consistent in terms of mapping how awakening gradually flourishes through an overall consistent virtue stillness wisdom process.
The broad umbrella of the boddhipakkhya dhammas share this overall order of events or things. And the big-picture suttas like AN10.2, AN11.2 and SN12.23 offer some interesting hints at the detailed linkages one should expect to see occurring internally as the development of the path progresses through right effort, right mindfulness / presence and right stillness/samadhi factors towards insight and liberation.
Nevertheless, the exact threshold at which the stillness-based process of insight eventuates the definitive cutting away of the underlying taints (āsava) and dooms one to a “definitive nibbana” albeit mentioned in MN70 is only clearly addressed in the MN111 and of course the very specific suttas of AN9 like AN9.34, AN9.38, AN9.39, AN9.40, AN9.44, and AN9.47.
Puna caparaṃ, āvuso, bhikkhu sabbaso nevasaññānāsaññāyatanaṃ samatikkamma saññāvedayitanirodhaṃ upasampajja viharati, paññāya cassa disvā āsavā parikkhīṇā honti. Ettāvatāpi kho, āvuso, sandiṭṭhikaṃ nibbānaṃ vuttaṃ bhagavatā nippariyāyenā”ti.
The way I make sense of the passage above is that it depicts the Buddha explicitly saying that the non-provisory nibbana (nippariyāyenā nibbānaṃ) is to be understood as something that comes with the attainment and transcending of the dimension of neither perception nor non-perception (nevasaññānāsaññāyatanaṃ).
A key issue that arises from this detailed description of how the totally ending or destruction of taints / fermentations (āsavā parikkhīṇā honti) is dependent on a vision and insight (paññāya cassa disvā) born of such immaterial attainment is that elsewhere the usual categorical definition of what right stillness consists of does not include such immaterial attainments but only the four jhanas (see SN45.8).
Cutting it short then, I would like to start this topic with aim of:
Bring together alternative descriptions of the specific process of stillness-born liberating insight which brings about the total ending or destruction of taints / fermentations found across AN9.
Investigate whether elsewhere in the EBTs one is able to find a model for liberating insight in which the four jhanas are sufficient and no immaterial attainment is required.
P.S.: Thanks in advance for abiding to the keep it tidy guideline of not diverting a topic midstream, and of course, and seeking to being always agreeable, especially when we disagree!