What does pari-mukha mean in 16 APS anapana sati? https://notesonthedhamma.blogspot.com/2019/07/what-does-pari-mukha-mean-exactly-in-16.html

excerpt:
Translation (from pali)
I've chosen the literal translation of near-the-mouth. In Theravada Pali Vinaya, pari-mukha is used in the context of facial hair or chest hair being in front of you. 

But what does it actually mean? 
To have 'sati' established 'near the mouth', or 'in front of you'?

Three logical possibilities
1) spatial coordinates only  (in front of you, near mouth, face, chest)
2) figurative only, not a literal interpretation of spatial coordinates, like "focusing on task at hand"
3) both one and two (it's possible the Buddha meant both, just like if you're using a cel phone, you're literally and figuratively focusing on the task in your hand)
There's an article discussing the use of that word here -- parimukhaṃ -- which interprets it literally, as you did, by referring to its being used literally in other texts like the Vinaya, the Abhidhamma, the Khuddaka Nikāya, and a Commentary.

Piya Tan disagrees, in his introduction to MN 118 he writes,


  2.4 PARIMUKHA
  2.4.1 Abhidhamma interpretation.
  Unlike in Hatha Yoga, in breath meditation the breath is not
  deliberately regulated, but a sustained effort is made to fix one’s awareness on the breath as it moves in and
  out in its natural rhythm. Those who follow the Abhidhamma and Commentarial traditions, teach that mindfulness should be focused at the nostril or the upper lip, wherever the contact of the breath is felt most distinctly. This tradition is mainly based on the Patisambhida,magga and Vibhanga interpretation of parimukham as being “at the tip of the nose or at the centre of the upper lip.”
  
  Parimukha literally means
  “around (pari) the entrance (mukha),” here always used idiomatically and as an adverb, meaning “in front.”
  This is the interpretation followed by U Thittila, Maurice Walshe, Soma Thera, and Ñānamoli &amp; Bodhi.


... and he includes a half a dozen footnotes as references for that last sentence.

He also wrote,


  In this connection, the Tiantai master, Zhìyǐ 智顗 (538-597), in his Tóngméng zhǐguān 童蒙止觀
  (Samatha and Vipasyana for Beginners), gives this advice for dealing with two kinds of distractions:
  
  
    What is a sinking mind? If during the meditation the mind is dull, confused or unrecordable,
    while the head drops, this shows a sinking mind. In such a case, it should be fixed on the tip of the
    nose to nail it there and to prevent it from wandering elsewhere. This is the way to regulate a sinking
    mind.
    
    What is a floating mind? If during the meditation, it drifts about and is uneasy, while thoughts
    follow externals, this shows a floating mind. In such a case, it should be pushed down and fixed on
    the navel to prevent thoughts from rising; thus the mind will be stabilized and will be easily quieted.
    
    Therefore, the absence of the sinking or floating state shows a regulated mind.
    (Zhìyǐ, Tóngmén Zhǐguān 童蒙止觀 in Lu K’uan Yü, 1964:126;41)
  


That latter reminds me of the little I was taught about Daoist meditation, incidentally.