I am not aware what PDS is referring to, if this is some kind of data(-format) the answer is: Once the OpenPGPCard update is out, you can sign any data using e.g., gpg, no need for the HSM2 (as long as you do not need multiple (>3) keys). But for now signing is not possible, as the Nitrokey 3 is as of now essentially a FIDO2 device.