How is the Pali Phase "Sabbakayapatisamvedi Assasissami... passasissamiti sikkhati..." Interpreted as per Different Linage?

What is the interpretation of the Pali phrase "Sabbakayapatisamvedi Assasissami... passasissamiti sikkhati..." this seems to be interpreted differently by different lineages. What are the different interpretations? What is the rationale behind the interpretation? How is the word Sabbakayapatisamvedi interpreted by the tradition, and what is the rationale behind it? How is it interpreted in the context of different meditation types (Kamatahan)? Is it connected to any stage of Insight Knowledge as per the interpretation? ___ With regard to one among many of the numerous occurrences of this phrase, the canonical text summarizing the 16 steps of Anapanasati meditation has the following passage: > Breathing in long, he discerns, 'I am breathing in long'; or breathing out long, he discerns, 'I am breathing out long.' Or breathing in short, he discerns, 'I am breathing in short'; or breathing out short, he discerns, 'I am breathing out short.' He trains himself, 'I will breath in sensitive to the whole body.' ---> (sabbakāyapaṭisaṃvedī assasissāmī’ti sikkhati) He trains himself, 'I will breath out sensitive to the whole body.' ---> (sabbakāyapaṭisaṃvedī passasissāmī’ti sikkhati;) He trains himself, 'I will breath in calming bodily fabrication.' He trains himself, 'I will breath out calming bodily fabrication.' ... Again this is only one occurrence among many, hence do not bias or limit the answer to the context of Anapanasati.