This is my attempt:

with Flow("mirror_sftp_to_gcs") as flow:
    password_secret_path = Parameter("password_secret_path")
    sftp_connection_info = Parameter("sftp_connection_info")
    password = GoogleSecretManagerSecret(password_secret_path)  # TODO: Cast function to convert to namedtuple
    host_path = Parameter('host_path')
    files = sftp_list_files(sftp_connection_info, password, host_path)
    downloaded_files = sftp_to_gcs.map(
        file_path=files,
        connection_info=unmapped(sftp_connection_info),
        password=unmapped(password),
        bucket=unmapped("snip")
    )

I get an error:

ValueError: Flow.run received the following unexpected parameters: password_secret_path

Very odd, the other parameters work, I am specifying them in a parameters kwarg in flow.run() in another file.