I am glad you posted Vince. It makes sense to me.
Regarding your question:
I learned that the main difference between any Ariya and an arahant is described, for example, here:
…”So too, friends, even though a noble disciple has abandoned the five lower fetters, still, in relation to the five aggregates subject to clinging, there lingers in him a residual conceit ‘I am,’ a desire ‘I am,’ an underlying tendency ‘I am’ that has not yet been uprooted”.
But…
…”As he dwells thus contemplating rise and fall in the five aggregates subject to clinging, the residual conceit ‘I am,’ the desire ‘I am,’ the underlying tendency ‘I am’ that had not yet been uprooted—this comes to be uprooted.”
https://suttacentral.net/en/sn22.89
The last is the arahantstage.
In my own words (please correct my if they are wrong): due to a strong habit in contact with ‘the world’ there arises in us constantly the conceit that there is a subject, an “I” who sees, feels, thinks, lives, plans, will die etc. This habit is stronger then the arising of hate and greed in contact with ‘the world’. It is all-pervading and, though, not Always present, it arises much more easy then hate and greed.
Near almost every experiences of us are coloured with the belief “I am”. This is conventionally called ‘subjectivity’. People who do not take everything so personal are much more stabel, happy, wise.
If pain would arise in us, probably, there would arise dosa too, as a habit, but also the conceit that an “I” feels the pain or has to bear the pain. This last is an even more stronger habit.
An arahant does not seem to have this anymore. The uprooting of the conceit “I am” was according to the Buddha the ultimate bliss.
“There is happiness and detachment for the one who is satisfied,
who has heard the Dhamma, and who sees,
There is happiness for him who is free from ill-will in the world,
who is restrained towards breathing beings.
“The state of dispassion in the world is happiness,
the complete transcending of sense desires,
But for he who has removed the conceit ‘I am’—
this is indeed the highest happiness.”
https://suttacentral.net/en/ud2.1
Siebe