You did not catch the main point.
1. Most Paṭicca Samuppāda processes start with a sensory input making one’s mind attached to an ārammaṇa. For example, take a cakkhu vinnana arising due to an arammana coming through the eyes.
– First, “Cakkhuñca paṭicca rūpe ca uppajjāti cakkhuviññāṇaṃ.”
– Then, “tiṇṇaṃ saṅgati phasso,” ““samphassa paccayā vedanā,” “samphassa jā vedanā paccayā taṇhā,” “taṇhā paccayā upādāna.”
2. At this point, one has upādāna, i.e., the mind has “pulled that arammana in, and is bound to it.”
– It is at this point that one starts accumulating abhisankhara via “avijja paccaya sankhara.”
– “nāmarūpa paccayā salāyatana” and so on come in after that. One starts visualizing related events (creating namarupa in mind) and using six ayatana to accumulate more kamma.
– That is discussed in “Difference Between Tanhā and Upādāna“; see #12 in particular. I just included that post in #6 of “Cuti-Paṭisandhi – An Abhidhamma Description.”
P.S. You wrote, “But the mind will analyse the object/nimitta and therefore contacts the pancakkhandha via manasikara cetasika. Thus I think the start is “nāmarūpa paccayā salāyatana” where the mind adjusts the mindset in regard to gati/experience/memory.” But “gati/experience/memory” comes in at the “samphassa paccaya samphassa-ja-vedana” step. That is what I was trying to explain.
– Yes. Grasping a new bhava happens at the “upādāna paccayā bhava.”
– But starting with an arammana (nimitta for the new bhava comes in as a sensory input) the mind gets to the “upādāna paccayā bhava” step WITHOUT going through the “nāmarūpa paccayā salāyatana” step.
– In fact, what I wrote above does not apply to that last citta vithi. That process of going back to the “avijja paccaya sankhara” step happens during a lifetime while accumulating more kamma!
– I got confused about your reference to the “nāmarūpa paccayā salāyatana” step. That step simply does not come in for the “maranasanna citta vithi” or the last citta vithi of a bhava.