SpamAssassin TMP folder setting?

[Brian Lewis]

I have created a TMPFS volume /tmp/mailscanner and have routed the work
directory settings in MailScanner to use this path.  I've also modified
the CLAMAV-wrapper to use this path as well for its extraction/testing.
The problem I see now is that SpamAssassin is constantly creating copies
of every email in the /tmp/ folder to run Pyzor/Razor2/DCC on it, I can
see this happening is the process list and see the files created/removed
if I constantly refresh /tmp/
Anyone know how I can have SpamAssassin use a different path for these
files so I can route them onto the TMPFS volume for better efficiency?
I've looked over everything about the SpamAssassin config files and can't
find any such setting.  Maybe I can modify a line in the spamassassin code?