[Avodah] halachik status of siddur (piyyut)

[Dov Bloom]

The thread was about: What is the halachic status of statements in Piyyutim? 
Well, on a topical piyut-halacha issue, here is a Pesach Piyyut mentioned by many rishonim.:

There is a well known piyut found in (some versions of) the Ashkenazi Piyutim for Shabbat Hagadol beginning "e-l e-lohai haruchot", written by R Yosef Tov Elem (Bonfils) who was a Gadol Hador in the generation before Rashi. RYTE was very much respected by later generations in France and Ashkenaz, Rashi mentions a tshuva of his, many Rishonim quote him, etc.

The Piyut goes over the halachot of Pesach , the first half being dinei Hag'ala and Bedikat Hametz and matza baking, while the second half is dinim of the seder.

Tosafot Pesachim daf 118 quotes a verse from this piyyut and ask a number of questions (teima...) as if it were any other psak or svara of a rishon that tosafos brings down, ayen sham.  

One of the Baale Hatosafot has a whole halachik perush on this piyyut which is brought down in its entirety in the Or Zarua Hilchot Pesach.

The daat.ac.il site has an article by a Dr Shalom Klein uncovering the direct halachik sources for the piyyut, with extensive footnotes. 

Moadim LeSimcha