Responsa sur Le Deutéronome 6:4

Nevertheless, I found that rabbi Yaakov [Tam]¹⁰³A most ‘famous’ Tosafot, where Rabbeinu [Yaakov] Tam (here called the R’I as the I represents the letter yod which also could mean Ya’akov.) argues with his grandfather, Rashi, as to the order of the parchment scriptures in the tewfillin. A search of בית חיצון yielded only one relevant source:
תוספות מסכת מנחות דף לד עמוד ב
...ומפרש ר"ת: קדש והיה כי יביאך מימין של קורא, ומשמאל של
קורא הוי שמע מבחוץ ואחריה והיה אם שמוע מבפנים וניחא השתא מה שחלקו וכן פירש רבינו חננאל בסנהדרין (דף פט.) כל בית החיצון שאינו רואה את האויר פסול כגון קדש ושמע וכן רב האי גאון
Our master rabbi Tam explained that the verses of “Make you first born unique to me” (Ex. 13:1-10), and “When you come to the land” (Ex. 13:11-16) are on one’s right of the one reading it, and to the left of the one reading it are “Hear Oh Israel” (Deut. 6:4-9) on the outside and afterwards “When you will certainly listen” (Deut. 11:13-21) as this now resolves the dispute, as was also explained by our master rabbi Khanan’el (Chananel ben Chushiel or Ḥananel ben Ḥushiel (Hebrew: חננאל בן חושיאל‎‎), an 11th-century Kairouanan Rabbi and Talmudist, was a student of one of the last Geonim. He is best known for his commentary on the Talmud. Chananel is often referred to as Rabbeinu Chananel - Hebrew for "our teacher, Chananel Rabbeinu Chananel" was born in 990 in Kairouan (modern Tunisia). R. Chananel studied under his father, Chushiel, head of the Kairouan yeshiva and through correspondence with Hai Gaon. He is closely associated with Nissim Ben Jacob in the capacity of rabbi and Rosh yeshiva of Kairouan. His most famous student is probably Isaac Alfasi.) quoting the tractate Sanhedrin 89a “Any [parchment] not on the outside, exposed to the outer air, is disqualified, as in “Make you first born unique to me” (Ex. 13:1-10)” and “Hear Oh Israel” (Deut. 6:4-9); so too was the custom of Rav Hai Gaon. wrote that the disqualification was not secondary to being prevented from ‘seeing the outside air’, except, specifically to the tefillin box worn on the head. However, the tefillin box worn on the arm it does not apply as there is no ‘outer box covering’ issues for the arm tefillin.