connecting the dots on why dukkha has not ceased yet in first jhāna (according to Vimuttimagga and Vism.) AN 4.163, AN 4.169, SN 48.40, AN 3.101

 

 AN 4.163 Asubha: Ugly

        AN ^4.163.1 - (painful practice + slow insight ← asubha topics + weak 5ind🖐️ )
        AN ^4.163.2 - (painful practice + fast insight ← asubha topics + strong 5ind🖐️ )
        AN ^4.163.3 - (pleasant practice + slow insight ← 4j🌕 + weak 5ind🖐️ )
        AN ^4.163.4 - (pleasant practice + fast insight ← 4j🌕 + strong 5ind🖐️ )

4.163.1 - (painful practice + slow insight ← asubha topics + weak 5ind🖐️ )

Katamā ca, bhikkhave, dukkhā paṭipadā dandhābhiññā?	And what’s the painful practice with slow insight?
Idha, bhikkhave, bhikkhu	It’s when a monk
a-subh-ānu-passī kāye viharati,	lives continuously-seeing the un-attractiveness of the body,
āhāre paṭikūla-saññī,	perceives the repulsiveness of food,
sabba-loke an-abhi-rati-saññī,	perceives dis-satisfaction with the whole world,
sabba-saṅkhāresu anicc-ānu-passī;	continuously-sees the impermanence of all co-activities,

The pleasant practice is of course 4 jhānas.

AN 4.169 describes the same practices as AN 4.163, but note the sutta title, it's describing that special samādhi in AN 3.101 not explicitly identifying first and fourth jhāna

AN 4.169 Sa-saṅkhāra: Extra Effort

        AN ^4.169.4 – (four types of people with 4 ways of getting fully nirvana'd)
        AN ^4.169.4.1 - (in the present life by making extra effort = austere practices + strong 5ind)
        AN ^4.169.4.2 – (when the body breaks up by making extra effort = austere practices and weak 5ind)
        AN ^4.169.4.3 - (in the present life without extra effort: 4 jhānas and strong 5ind)
        AN ^4.169.4.4 - (when the body breaks up without extra effort: 4 jhānas and weak 5ind)

Recall (above) that AN 4.163 describes those 5 types of asubha practices as "dukkha patipada", not "domanassa". 
AN 3.101 first jhāna has dukkha as a factor
So this explains how vimuttimagga (and vism. copying vimt.) 
states that asubha (31 body parts meditation) is limited to first jhāna, 
and that dukkha (physical pain) can be a factor in first jhāna if doing asubha.
Note that the Theravada SN 48.40 is corrupt, they say dukkha  ceases in first jhāna, and domanassa doesn't cease until second jhāna. 
But the other 4 EBT schools, their version of SN 48.40
has the jhāna factors cease in the correct order

(AVS) Aviparitaka Sutra (agama parallel to SN 48.40)

(has domanassa, dukkha, somanassa, sukha and upekkha cease successively)
(domanassa-indriya [mental pain] ceases in 1st jhāna)
(dukkha-indriya [physical pain] ceases in 2nd jhāna)
(somanassa-indriya [mental pleasure] ceases in 3rd jhāna)
(Sukha-indriya [physical pleasure] ceases in 4th jhāna)
(upekkha-indriya [physical & mental lack of sāta] ceases in saññā-vedayita-nirodhaṃ )

At least 4 distinct school of Buddhism agree on AVS, against one Theravada SN 48.40

These texts and commentaries from various schools of Buddhism vary on their interpretation of AVS (Aviparitaka Sutra), but they all seem to preserve the same consistent version of AVS, whereas the SN 48.40 Theravada Pali is an outlier that differs drastically from AVS.

1. Abhidharmamrta(rasa)-sastra (sarvastivada school)
2. Tattvasiddhi (or * Satyasiddhi-sastra, pé Cheng shi lun) of the Darstantikas or the Bàáhusrutiyas SCHOOL
3. Yogacarabhumi (tiita Yu qie shi di lun) of the Yogacara school.
4. As to the Sautrantika views, I shall refer to the Abhidharmako s´abhasya by Vasubandhu in the fourth or fifth century A.D. Although this treatise describes itself as ‘‘a presentation of the Abhidharma as taught by the Vaibhasikas’’, its author has evident sympathies for the Sautrantikas. (Sautrantikas is to be treated as a different school of thought than Sarvastivada)

Conclusion

Connecting the dots on AN 4.163, AN 4.169, SN 48.40, AN 3.101,
we can see there is an EBT basis for Vimt. (and Vism.) saying that Asubha (31 body parts) meditation,
can only take you up to first jhāna, and that dukkha is still present in that first jhāna.