Getting back to Arso regarding the yichus question. The rabbi I know who�s knowledgeable in this field sent me copies of several pages of a sefer written on this with copious references to other sources. It�s not on Hebrew books and I�m not going to write up and translate the entire thing. I can send you the book title and page numbers if you�re that interested in getting a physical copy.
Or if there�sa way to upload them here, and you want them, lmk.