From: Rabbi Moshe Sofer
To: Rabbi Pinchas Leib Munk
The Chasam Sofer resolves the Hagahos Ashri's difficulty in Bava Basra 156 by distinguishing the tzror v'zorko-stage minor, who benefits from neither the shlichus-based nor the rabbinic-enactment-based mechanism of zochin. He also rules that orphans presented with an iska document owe only the principal, since the claim of no profit is a mi'ut ha'matzui argued on their behalf, and any profit obligation would derive from dinei d'garmi—a kenas not collectible from heirs.
Source: Shu"t Chasam Sofer CM §136