And speaking of the last Tshuva on manhagei chassidim, where he refers to the Yismach Moshe as ידיד נפשי, although they never met each other but just by correspondence. Here is an amazing episode written by the שבט מיהודא the Rav of Satmar - SIL of the Chasam Sofer's son Reb Yosfa, and talmid of the Ksav Sofer, what he heard from his uncle Reb Shimon Sofer.