what I said about breath meditation was just a side comment. We here know how pervasive it is that breath meditation is wrongly interpreted as anapanasati, and anatta as no self.
For the topic at hand, we know that:
Sakkaya = pancupadanakkhandha
sakkāya ditthi = wrong views that sakkaya is worthwhile to be taken as me, mine, the 20 ways you mentioned.
… and also
pancupadanakkhandha is a subset of pancakkhandha
“Sakkaya is the origin of Sakkaya Ditthi.”
— I tend to think that Sakkaya Ditthi is “in” pancupadanakkhandha (probably in the sankharakkhanda).
“…But even with Sakkaya Ditthi removed one would still Sakkaya until one has removed all Avija.”
— This is true. Sakkaya Ditthi is removed at the sotapanna stage. At this stage, there is still pancupadanakkhandha, but it has reduced by a “huge” amount.
“As long as the pancakkhandha is there for the satta, the “perception” of “I, me” or mana will be there.”
— I’d say that “As long as pancupadanakkhandha is there …”
For an arahant, there is still pancakkhandha (until parinibbana), but no perception of “I, me” or mana.