As OpenSSH is expecting a PKCS11 "format" Card, I use the OpenSC library (opensc-pkcs11.so) for SSH command line authentification.
The SmartCard content doesn't appear in the KeyChain, if I'm not mistaken the SmartCard Services (TokenD) has been abandoned by Apple and now use PCSC
( wich doesn't seeam usable with OpenSSH)
On MacOS 10.15 Catalina at least, I can use native ssh client with "PKCS11Provider /usr/lib/ssh-keychain.dylib" in the ~/.ssh/config file and Yubikey works for passwordless login. This is apparently supported since MacOS High Sierra. Cyberduck should also support this since it's build in to MacOS.