Hi Frankk (nice to see you posting on jhana over here). To play devil's advocate on your "second installment" on circular reasoning, maybe Analayo does have an at least arguable point (hadn't thought about it myself this way before)? His logic seems to be that later enlightenment factors are dependent on earlier enlightenment factors, so concentration must depend on the five earlier ones. If Sariputta is observing their arising and passing, then on the passing of an earlier factor, the later enlightenment factor, concentration, must also be consequently absent at the time. That seems to be his argument, which doesn't seem circular to me.[/quote]
(7sb) satta -(sam)-bojjh-aṅgaṃ, seven-awakening-factors are not just a causal sequence, and there are many ways to use it.
For example, 4 jhānas can be seen as 4 quality levels of samādhi-sambojjhanga.
But also, 7sb can be seen as factors in each of the 4 jhānas.
In third jhāna, the formula explicitly lists (S&S🐘💭) sati & sam-pajāno, remembering & lucid-discerning , corresponding to (7sb → 1. 🐘 sati) and (7sb → 2. 💭🕵️ Dhamma-vicaya), and also 7sb7 (upekkha). Sukha, which has 7sb5 (passadhi/pacification) as a prerequisite, so even though 7sb5 not explicitly stated, it's there in 3rd jhāna. 7sb3 viriya, is also not stated, but it's there as well. So of the 7 factors in 7sb, only piti is not present in third jhāna.
Therefore 7sb is not a casual sequence where all previous factors have to be abandoned to reach the next one.
At earlier times, but maybe not in EBMS, I think Bhikkhu Anālayo had tried to prove his redefintion of what absorption means by claiming all four jhānas, including first jhāna, are ekaggata (single preoccupation).
He may have realized the futility of that strategy and so now in EBMS just uses empty sophistry and circular reasoning, and a whole lot of fallacious disingenuous argumentation tactics. The key to pulling off his deception, is that for each fallacious critical error, he'll also have 10 valid and logical/reasonable points to make, so that most people will be overwhelmed by the ten to one ratio (very approximate) to give an air of authenticity and legitimacy. But you only need one fatal flaw to blow away the whole thing, and most people haven't studied the EBT and understand it well enough to detect fraud.
Along the lines of 7sb, he also tries to say that vossagga is not the final release of nirvana, but a prerequisite condition for first jhāna. There are so many flaws in his work I don't have time to expose them all, so I have to just focus on the big ticket items.