generation of patisandhi citta is not conditioned only by cuti citta/abhidhamma is vipassana

The concept of cuti patisandhi cittas- ie. generation of patisandhi citta conditioned by cuti citta in a minute fraction of a second- is a very important concept mentioned in Abhidhammaththa Sangaha.

No, every abhidhamma and sutta described that whatever kamma of javana in the past, just in a minute or in the trillion rebirth ago, determine the nature of the next life's Paṭisandhi-citta (resultant). And the same kamma in the past of present life's Paṭisandhi-citta (resultant) let present life's Bhavaṅga-citta (resultant) and Cuti-citta (resultant) arise, too.
If you recite and memorize chapter 4th and 5th of abhidhammatthasaṅgaha you will notice that maraṇāsannavithī and paṭisandhi-citta which appear in 4th chapter, that you mentioning, were specially described in 5th chapter and in 5th chapter, the title: "iii. Fourfold Kamma" come before the title: "iv . Procedure with Regard to Decease and Rebirth", because most of the kammas in iii. cause the resultants in iv.
Furthermore, there are too many cause more than kamma condition paṭisandhi-citta, such as many sahajāta-nāma/rūpa, many past upanissaya-nāma/rūpa, etc. But many cannon often focus at kamma as the main cause of paṭisandhi because of paṭiccasamuppda.
For conclusion, you have to recite paṭiccasamuppāda, then read this answer:
Sacca-pabba Is The Reason That Commentary Commented "Viññāṇa Is Jāti And Paṭisandhi", Right?
Another mention of you:

This is so important that only by describing the mechanism of cuti-patisandhi in this way the main teaching of Buddhism that there is no soul or ego (anaththa) can be justified. Can I find any reference in Abhidhamma Pitaka.

Abhidhamma is vipassanā-cannon.
Commentary said:

The vinaya is too much adhisīla. The suttanta is too much. The abhidhamma is too much vipassanā.

Also commentary said:

Sāriputta school studied abhidhamma.

And commentary said:

1st saṅgāyanā saṅga gave majjhimanikāya to sāriputta school students for keeping by reciting and memorizing.

Another commentary said:

Majjimanikāya is mahāvipassanā (too many vipassanā).

Who is venerable sāriputta, aggasāvaka?

187. Bhikkhus, I do not know of any other person who could follow up the teaching proclaimed by the Thus Gone One other than Sāriputta. Bhikkhus, Sāriputta follows up the teaching proclaimed by me.

http://84000.org/tipitaka/pitaka2/v.php?B=20&A=585&Z=627&eng=metta_e

Path of purification was written follow sāriputta's cannon, paṭisambhidāmagga. Many quotes and sequence in Path of purification follow paṭisambhidāmagga.
According to mahāgosiṅgasālasutta venerable Sāriputta was a teacher of venerable Mahākassapa, venerable Mahāmoggallāna, venerable Mahākassapa, venerable Anuruddha, venerable Ānanda, and venerable Revata, too (except ānanda, sotāpanna-ariya, the others were arahanta-ariya).
According to understanding section in Path of purification, that mostly describing about vipassanā (adhipaññā-sikkhā), you can found too much abhidhamma in this section of Path of purification.
So, your understanding about relationship between abhidhamma and anattā is correct. But your abhidhamma knowledge still wrong.