I meant well known among talmidim of the Brisker Rov and talmidim of Rav Gorelick.
There’s no stira about people, including the CC, having esteemed RAIK when he was in Europe and prior to his having moved to EY and taken the public zionistic positions he took that he had not adopted prior to that time, while losing that esteem once he took his (new) public positions in EY.
As far as documenting Kasher’s forgeries, google “Kalir, False Accusations, and More” for a seforimblog article by Prof. Marc B. Shapiro of the University of Scranton where he documents various forgeries and other misdeeds by Kasher. Some based on his own research and some based on the research of others – including his citing Zvi Weinman’s sefer I mentioned, Mi-Katovitz ad Heh be-Iyar, which Prof. Shapiro notes Weinman has shown, including with visual evidence, Kasher’s forgeries on the athalta di-geula letter.