Vipassana on arupa worlds

Just trying to answer my question in a partial and tentative way: according to Mahasi Sayadaw, in its Discourse on Sakkapañha Sutta:

A stream-winner in the immaterial world (arûpaloka) will not forget to practise mindfulness. He can contemplate the mental processes and attain Arahantship. [1]

Anyway in another passage he gives importance to having a physical body:

For, as a discourse in the Anguttaranikâya says, the physical body of a deva is pure and radiant and the Dhamma becomes clearly manifest to one who has practised in his previous life. It may take some time to recollect, but recollection is instantly followed by attainment of insight knowledge. [2]

So it seems that in general it would be possible to practice vipassana in an arupa world, but only if one already practiced it presumably with a physical body.

According to AN 8.29, being reborn in the formless realm is considered to be one out of eight "inopportune" moments that are not right occasions for living the spiritual life:

...Again, a Tathāgata has arisen in the world … and the Dhamma leading to peace, nibbāna, and enlightenment is taught as proclaimed by a Fortunate One. But a person has been reborn in a certain order of long-lived devas. This is the fourth inopportune moment that is not the right occasion for living the spiritual life.

and Ven. Bodhi's note citing the Comy. in his "Numerical Discourses":

Dīghāyukaṃ devanikāyaṃ. Mp: “This is said with reference to the order of non-percipient devas (asaññaṃ devanikāyaṃ).” However, it also seems to apply to the devas of the formless realm, who (because they lack bodies) cannot hear the Buddha or his disciples teach the Dhamma and thus cannot attain even the path of stream-entry.

Goenka said: It is clear that vedana as a part of the nama that is firmly rooted in kaya is what the Buddha wanted us to focus on when he talked about meditation to eradicate suffering.

The suttas do not conform with this. To quote:

On cognizing an idea with the intellect, he isn't infatuated with pleasing ideas, and doesn't get upset over unpleasing ideas. He dwells with body-mindfulness established, with unlimited awareness. Having thus abandoned compliance & opposition, he doesn't relish any feeling he feels — pleasure, pain, neither-pleasure-nor-pain — doesn't welcome it, doesn't remain fastened to it. As he doesn't relish that feeling, doesn't welcome it, & doesn't remain fastened to it, delight doesn't arise. From the cessation of his delight comes the cessation of clinging. MN 38

~~~

"If anyone were to say, 'Feeling at the intellect is the self,' that wouldn't be tenable. The arising & falling away of the intellect are discerned. And when its arising & falling away are discerned, it would follow that 'My self arises & falls away.' That's why it wouldn't be tenable if anyone were to say, 'The intellect is the self. MN 148

Goenka said: This is also the reason why brahmas from arupabrahmaloka cannot practise Vipassana

MN 1 & MN 111 states vipassana can be practised on arupa jhana. To quote:

the dimension of the infinitude of space as the dimension of the infinitude of space... the dimension of the infinitude of consciousness as the dimension of the infinitude of consciousness... the dimension of nothingness as the dimension of nothingness... the dimension of neither-perception-nor-non-perception as the dimension of neither-perception-nor-non-perception...does not conceive as 'mine'

Goenka said: and why the Buddha could not give Dhamma to his past teachers of arupa jhanas (seventh and eighth jhanas/dhyanas).

The Buddha could not give Dhamma to his past teachers because they died. Refer to MN 26.

In the fifth to eighth jhanas, jhanas the mind is set free from the body and thus there is no experience of vedana.

MN 111 explains there is vedana in arupa jhana. To quote:

Sariputta entered & remained in the dimension of the infinitude of consciousness. Whatever qualities there are in the dimension of the infinitude of consciousness — the perception of the dimension of the infinitude of consciousness, singleness of mind, contact, feeling, perception, intention, consciousness, desire, decision, persistence, mindfulness, equanimity, & attention — he ferreted them out one after another.

Goenka said: Therefore, these brahmas lack rupa and cannot experience body-sensations. Hence, the practice of the awareness of vedana is not possible for them and they cannot walk on the path of liberation.

'Vedana' does not mean 'body-sensations'. To quote:

And why do you call it 'feeling' ('vedana')? Because it feels, thus it is called 'feeling.' What does it feel? It feels pleasure, it feels pain, it feels neither-pleasure-nor-pain. Because it feels, it is called feeling. SN 22.79

In fact, what are generally regarded as 'body-sensations' or 'stress' are generally 'sankhara' (mental formations of lust, hatred & delusion) that condition & get stored in the physical body rather than 'vedana' (pleasant & unpleasant feelings). To quote:

For him — infatuated, attached, confused, not remaining focused on their drawbacks — the clinging to the five aggregates head toward future accumulation. The craving that makes for further becoming — accompanied by passion & delight, relishing now this & now that — grows within him. His bodily disturbances & mental disturbances grow. His bodily torments & mental torments grow. His bodily distresses & mental distresses grow. He is sensitive both to bodily stress & mental stress. MN 149

If my understanding is correct,"mind states correlate with realms of rebirth".I don't think you can practice Vipassanna in any Jhanic State.Not even the first jhana (rupajhana). So i don't think any one reborn in a corresponding jhanic realm can practice vipassanna as they are in Absorbtion.I think those born in a non-jhanic realm such a tusita realms etc can hear the dharma.But not those in the rupa or arupa jhanas. Except for the Five Pure Abodes i think their an exception.Though forgive me if i am mistaken.

In the arupa worlds you cannot hear the Dhamma as you do not have this faculty, also the mental process is too subtle making it not possible to meditate on it. But if you have experiences even the 1st state of sainthood you can progress from here to the final goal.

By the way, living in an arupa world would imply in my understanding that it is possible the arising of a mind consciousness (manovinnana) without a physical sense base (such as our heart base or hadaya-vatthu): is this assumption correct?

My thinking is also that the heart base does not have a physical associated location in the arupa realm as there is nothing physical or corporeal here.

In addition, in the brahma world as you quoted you to not have physical sensation relating to the elements but sensations are present in the arupa cittas. See 121 cittas in Abhidhamma.