Just as an aside, neither rav pam nor rav miller went to mixed colleges; that’s just not true. Rav miller went to YU, which isn’t mixed. Rav Miller did go to public school beforehand, because there were no yeshivos.
Chaim berlin didn’t “send” talmidim to college(with some exceptions) they mostly allowed it; same with torah vodaas. Mir clamped down hard on college when rav shmuel became rosh yeshiva.
Nowadays yeshivos only allow touro/other “Jewish” colleges.