The rūpa (physical body) is active in 4 jhānas, not transcended until to arūpa (formless) samādhis

In this article, we'll gloss two key words. Rūpa, and nānatta (diversity).
Glossing the base of infinite space formula,
which is the samadhi attainment right above fourth jhana.
It shows that, if that is the attainment where one transcends sights, sounds, smells,....,
then it means in the 4th jhana, and first through 4th jhana,
one has NOT transcended sights, sounds, smells...,
i.e. the 5 sense faculties of the body are still active.

ākāsānañcā-(a)yatanaṃ

Space-infinitude-dimension is the 5th of the 9 progressive samādhi attainments.

attainments 1-4 are the four jhanas.

STED (smd 5) ākāsānañcā-(a)yatanaṃ

STED (smd 5) Space-infinitude-dimension

sabbaso rūpa-saññānaṃ samatikkamā	(with) complete [physical] form-perceptions transcending,
Paṭigha-saññānaṃ atthaṅgamā	(with) resistance-perceptions disappearance,
nānatta-saññānaṃ a-manasikārā	(and) diversity-perceptions; non-attention (to them),
‘an-anto ākāso’ti	[perceiving,] 'In-finite space,'
ākāsānañcā-(a)yatanaṃ upasampajja viharati.	Space-infinitude-dimension, (he) enters, dwells.

What is the rūpa (form) that is being transcended?

Glossing Rūpa

KN Snp 5.17 piṅgiyamāṇava-pucchā (p's-questions)

♦ 16. piṅgiyamāṇavapucchā (KN 5.71)	5:16  Piṅgiya’s Questions
♦ 1126.	I’m old & weak,
(iccāyasmā piṅgiyo)	my complexion dull,
♦ “jiṇṇohamasmi abalo vītavaṇṇo,	I’ve blurry eyes
♦ nettā na suddhā savanaṃ na phāsu.	and trouble hearing—
	but may I not perish
♦ māhaṃ nassaṃ momuho antarāva	while still deluded,
	confused!
♦ ācikkha dhammaṃ yamahaṃ vijaññaṃ.	Teach me the Dhamma
	so that I may know
♦ jātijarāya idha vippahānaṃ”.	the abandoning here
	of birth & aging.
♦ 1127.
(piṅgiyāti bhagavā)	The Buddha:
♦ “disvāna rūpesu vihaññamāne,	Seeing people suffering
♦ ruppanti rūpesu janā pamattā.	on account of their bodies—
	heedless people are afflicted
♦ tasmā tuvaṃ piṅgiya appamatto,	on account of their bodies—
	then heedful, Piṅgiya,
♦ jahassu rūpaṃ apunabbhavāya”.	let go of the body
	for the sake of no further becoming.

MN 13 rūpā, sarīraṃ, kāya of beautiful girl aging, dying

From this passage you can see rūpa’s relationship to kāya (body).

♦ 171. “ko ca, bhikkhave, rūpānaṃ assādo?	"Now what, monks, is the allure of forms?
seyyathāpi, bhikkhave, khattiyakaññā vā brāhmaṇakaññā vā gahapatikaññā vā pannarasavassuddesikā vā soḷasavassuddesikā vā, nātidīghā nātirassā nātikisā nātithūlā nātikāḷī nāccodātā paramā sā, bhikkhave,	Suppose there were a maiden of the noble caste, the brahman caste, or the householder class, fifteen or sixteen years old, neither too tall nor too short, neither too thin nor too plump, neither too dark nor too pale.
tasmiṃ samaye subhā vaṇṇanibhāti?	Is her beauty & charm at that time at its height?"
‘evaṃ, bhante’.	Yes, lord.
yaṃ kho, bhikkhave, subhaṃ vaṇṇanibhaṃ paṭicca uppajjati sukhaṃ somanassaṃ —	"Whatever pleasure & joy arise in dependence on that beauty & charm:
ayaṃ rūpānaṃ assādo.	That is the allure of forms."

(rupa applied to same beautiful girl aging, getting old and ugly)

(note this next part appears in MN 10 under kāya anupassana (body contemplation - rupa, sarira, kaya all pointing to anatomical body here)

♦ 172. “puna caparaṃ, bhikkhave, tameva bhaginiṃ passeyya sarīraṃ sivathikāya chaḍḍitaṃ —	"Again, one might see that very same woman as a corpse cast away in a charnel ground —
ekāhamataṃ vā dvīhamataṃ vā tīhamataṃ vā, uddhumātakaṃ vinīlakaṃ vipubbakajātaṃ.	one day, two days, three days dead, bloated, livid, & oozing.
taṃ kiṃ maññatha, bhikkhave, yā purimā subhā vaṇṇanibhā sā antarahitā, ādīnavo pātubhūtoti?	What do you think: Has her earlier beauty & charm vanished, and the drawback appeared?"
‘evaṃ, bhante’.	Yes, lord.
ayampi, bhikkhave, rūpānaṃ ādīnavo.	"This too, monks, is the drawback of forms.

MN 137 glossing nānatta (diversity perceptions)

(upekkhā nānattā: equanimity based on diversity)

Katamā ca, bhikkhave, upekkhā nānattā nānattasitā?	And what is equanimity based on diversity?
Atthi, bhikkhave, upekkhā	There is equanimity towards
rūpesu,	sights,
atthi saddesu,	sounds,
atthi gandhesu,	smells,
atthi rasesu,	tastes,
atthi phoṭṭhabbesu—	and touches.
ayaṃ, bhikkhave, upekkhā nānattā nānattasitā.	This is equanimity based on diversity.

(upekkhā ekattā: equanimity based on unity)

Katamā ca, bhikkhave, upekkhā ekattā ekattasitā?	And what is equanimity based on unity?
Atthi, bhikkhave, upekkhā	There is equanimity based on the
ākāsānañcāyatana-nissitā,	dimensions of infinite space,
atthi viññāṇañcāyatana-nissitā,	infinite consciousness,
atthi ākiñcaññāyatana-nissitā,	nothingness, and
atthi neva-saññā-n-āsaññāyatana-nissitā—	neither perception nor non-perception.
ayaṃ, bhikkhave, upekkhā ekattā ekattasitā.	This is equanimity based on unity.

Tatra, bhikkhave, yāyaṃ upekkhā ekattā ekattasitā taṃ nissāya taṃ āgamma yāyaṃ upekkhā nānattā nānattasitā taṃ pajahatha, taṃ samatikkamatha. Evametissā pahānaṃ hoti, evametissā samatikkamo hoti.

Therein, relying on equanimity based on unity, give up equanimity based on diversity. That’s how it is given up.

so if 5 sensory faculties are inactive in a-rūpa samadhis, what do you think that means about 1st jhāna to 4th jhāna (rūpa samadhis)?

--jhana is based on perception of "multiplicity of sensory experiences." In practical terms, this means that the mind is in contact with blissful bubbly sensations, surges/currents/confluences/settling of energies; the occasional, gentle impingement of sounds and random tactile sensations don't knock one out of the seclusion peace, but are in general registered as either innocuous, neutral sensations, or a part of the vibrant field of pleasant experience.
The passages also make clear that "singleness" of perception in the formless means the suspension of sensory awareness, and this is made distinct from experiences of the form attainments (the four jhanas).