From what I understand these values cannot be modified within the CF files. I haven't personally tested modifying these, you may have some success but I would advise against it as it would not officially be supported.
I would recommend deploying a standalone SpamAssassin server that you can fully customize. There is a virtual appliance option you can also deploy in your environment. More information on this can be found here: https://portal.smartertools.com/kb/a2718/install-and-configure-spamassassin-virtual-appliance.aspx
I hope this helps.
Technical Support Specialist / Internal IT