PGP/MIME guidance for multipart/signed with v6 signature

PGP/MIME (RFC 3156) specifies a micalg= parameter that's present for the sake of one-pass processing of the message.

With the salt added to v6 signatures, micalg= alone is insufficient to permit one-pass processing of a PGP/MIME multipart/signed message. Maybe we want to have this document update RFC 3156 by adding a pgpsalt= parameter?