Date: 17 Menachem Av 5594
From: Rabbi Moshe Sofer
To: Rabbi Yeshaya
A pair of tefillin was found where the shel yad formatted V'haya Im Shamoa as stumah (per the Taz) while the shel rosh formatted all parshiyos as pesuchos (per the Magen Avraham). The Chasam Sofer rules this is not a self-contradiction, since the shel rosh's separate parchments eliminate the pesucha/stumah requirement, and the established Ashkenazic practice validates all-pesuchos formatting.
Source: Shu"t Chasam Sofer OC §4