יציב פתגם - מהותה ואמירתה בחג השבועות

On the second day of שבועות, following the first פסוק of the הפטורה [1], a פיוט beginning יציב פתגם is sung by the בעל קריאה. This פיוט is part of a series of פיוטים related to the קריאות of שבועות, the original purpose of which was to serve as a נטילת רשות [2] to say the תרגום of the הפטורה [3]. (Evidently there was a custom to say the Aramaic translation of the הפטורה, similar to the custom - today practiced only by Yemenites [4] - of saying the תרגום of the פרשה during קריאת התורה.) Today, to my awareness, there is no community that says תרגום of the הפטורה, but the custom of saying the נטילת רשות stuck.

Being that יציב פתגם is a נטילת רשות for saying תרגום, it is said/sung following the first פסוק of the הפטורה, which is where the תרגום would, theoretically, begin.

Addenda

This custom is not completely universal: in Pozna it was not said (לבוש או"ח תצד:א). All of the various shuls I have attended over the years on the second day of שבועות do say it; considering, however, that they all, broadly speaking, follow נוסח אשכנז - מנהג פולין, this does not necessarily indicate much as regards other traditions. As for specific communities that I have not personally visited, I have only been able to find written record of יציב פתגם being said in Telz (מנהגי ישיבת טלז פרק ט - יום שני דשבועות). [5] It also appears in סידור קרני הוד (מכון מעדני אשר תשסד), which intends to be a completely accurate נוסח ספרד סדור, as indicated by the inside cover.

As an aside, the standard (מנהג פולין) tune for יציב פתגם is (nearly) identical to the rendition of אדון עולם sung at the end of davening in many ישיבות.

[1] ר אברהם Klausner, מ"ב תצד:ב; ספר המהנגים אות קלב. According to שו"ע הרב (או"ח תצד:ז), however, this would be considered a הפסק, to which end, he suggests placing prior to the ברכות of the הפטורה, or, better yet, not saying it altogether. This is indeed the custom in Lubavitch today (told to me by R Avrohom Bergstein of Anshei Lubavitch - Fair Lawn).

[2] lit. "taking permission", a נטילת רשות typically takes the form of a paragraph and/or פיוט which serves to introduce other פיוטים etc. that are not part of the ordinary סדר התפלה. See, for example, paragraph beginning מסוד חכמים ונבונים at the beginning of  חזרת השץ (according to נוסח אשכנז) on יו"ט.

[3] https://www.toviapreschel.com/yetziv-pitgam/

[4] told to me R Ronen Shaharabani of Cong. Magen Abraham (Mill Basin - נוסח תימן)

[5] I am unsure as to the מנהג הגרא on this matter: on one hand, סידור ווילנא (Mesores 5753) does include יציב פתגם in the הפטורה for the 2nd day of שבועות, whereas סידור אזור אליהו (מכון אזור אליהו תשפ), as well as סידור ע"פ נוסח הגרא (מוסד הרב קוק 2019) does not.