From: Rabbi Moshe Sofer
To: Rabbi David Katz
The Chasam Sofer addresses whether the mi'uch u'mishmush test remains reliable when a lung adhesion coincides with a wound on the chest wall. While the Simlah Chadashah rules that communities with a stringent custom may not rely on the mi'uch test in such cases, and the Beis Efrayim extends this stringency to new communities, the Chasam Sofer disagrees and rules leniently when the animal belongs to a Jew and significant financial loss would result.
Source: Shu"t Chasam Sofer YD §41