Tim,
        I control my FULL backups by using SERVER SCRIPTS that change the
COPY MODE of the MANAGEMENT CLASS to ABSOLUTE and do an ACTIVATE to put the
change of the POLICY SET into use.  Then the backup for servers using that
MANAGEMENT CLASS will be doing FULLS.  Right after the backup starts another
SERVER SCRIPT sets the COPY MODE back to MODIFIED so the next time through
is an incremental.
Matt