DHKEM requires the ability to get the public key from a private key, at https://www.rfc-editor.org/rfc/rfc9180.html#section-3-2.4:

pk(skX): The KEM public key corresponding to the KEM private key skX.

Back in JDK-8305310, we did this for EC and XDH in the SunEC provider. The function is still not available in PKCS #11. Note that there is no XDH support in SunPKCS11 yet.