We do not have any current PKCS11 support in MINA SSHD. We do support SSH agents in general, so one could add the necessary support - Java even seems to have some PKCS11 support in it ( https://docs.oracle.com/javase/7/docs/technotes/guides/security/p11guide.html) but I have never looked into it.
Anyway, it is not a very popular request, so given the very limited R&D resources we have we need to focus on bugs and most widely used features. That being said, if you do decide to add such support, please feel free to contact us via this mailing list for any questions you might have during development. Also, please consider donating the code back to the project so others may also be able to use it - we appreciate and gladly acknowledge such contributions.
