According to the traditional Theravada accounts…
Of particular interest to me was the sentence, “The fault does not lie with arahantship but with the state of a layman, because it is too weak to support arahantship.”. I was contemplating why this might be so and why the lay-life might be too weak to sustain arahantship. Immediately I came to reflect on the nature of nama-rupa (name and form) as explained by Nanananda et.al. and it became clear that the principle insight of the noble disciple (“Whatever is subject to arising is all subject to cessation”) involves understanding the reality of experience in a manner that is increasingly divergent and divorced from the understanding of the world at large. As one progresses in terms of Dhammic understanding and paticcasamuppada becomes a more natural and instinctive frame of reference by which to understand life, the terms of reference by which the lay-life is lived, become increasingly foreign, alienating and irrelevant."If a layman attains arahant-ship, only two destinations await him; either he must enter the Order that very day or else he must attain parinibbàna"
Milindapanha III.19
"You say that if a layman attains arahantship he must either enter the Order that very day or die and attain parinibbàna. Yet if he is unable to find a robe and bowl and preceptor then that exalted condition of arahantship is a waste, for destruction of life is involved in it."
"The fault does not lie with arahantship but with the state of a layman, because it is too weak to support arahantship. Just as, O king, although food protects the life of beings it will take away the life of one whose digestion is weak; so too, if a layman attains arahantship he must, because of the weakness of that condition, enter the Order that very day or die."
Milindapanha III.62
As suttas like MN 1 show, the Buddha advised that the sekha should try to see without conceiving what is seen as discrete entities, yet the cornerstone of the lay-life is centred in the assumed existence of entities – things (or dhammas). The lay-life solidifies these entities, attributing qualities to them, classifies and categorizes them, and engages with them as if these imputed qualities were inherently existing. The lay-life involves communication and engagement with others, and such engagement and communication (unless it is specifically focused on Dhammic truths) presumes the inherent existence of conceptualizations and perceptions which have no inherent existence. The sekha is aware of the error in this, but the lay life is fundamentally unable to support such a mode of understanding, which would leave the worldling utterly bewildered. Were one to actually attain arahantship the divergence between reality and the worldlings’ misconceptions of it would be so diametrically opposed that what is said in the Milindapanha actually makes a good deal more sense. It need not be taken as some arbitrary prophecy that a stray heifer or other such misfortune will befall an arahant and lead to their premature death, but rather, that lay-life and the ignorance of dhammas in which it is rooted, can no longer sustain one who has totally transcended that ignorance. To engage with that lay life, would be to engage with that which the arahant knows as little more than a house of cards. The engagement would be little more than a show – and as such, it would be inauthentic. The lay-life cannot handle the lay-arahant's authenticity.
Presumably if the lay-life cannot support the weight of arahantship, then previous noble attainments must also apply a certain weight to this precarious house of cards. The weightier the insight and wisdom, the more diametrically opposed the sekha stands in contradistinction to the world and its ways. For the lay sekha, this poses an interesting conundrum… since one has the potential to see correctly, but also the residual tendency to see incorrectly… is it necessarily in the sekha’s best interests to strive onwards, knowing that the weight of their attainment will put them diametrically opposed to the world in which they live? As the Milindapanha suggests, yes, such a person could ordain and remove that tension, but were they to remain in the lay life, would it necessarily be beneficial for them to advance as far as possible along the Dhammic path in this lifetime and increase this weight? If, as the suttas explain, such an individual is destined to attain nibbana within seven lifetimes at most, is living a life which is increasingly fundamentally opposed to, and at odds with the world’s worldliness, actually the best thing for the sekha to do? Is it best to become increasingly 'indigestible'? And if that is not the best thing for a sekha to do, then what actually is a sekha to do?
There's some food for thought.

I look forward to hearing your thoughts and experiences in relation to this matter.
Metta,
Paul.
