Disabling rsyslog rate-limiting just for audit/audispd

With the caveat that I am perhaps asking the wrong audience, I'm hoping that someone has hit this issue before, and possibly solved it. I've set up a number of servers in my environment to forward all audit log entries via audispd and rsyslog to a central rsyslog receiver where they are parsed and saved. All that is working (audit is sent with LOG_LOCAL6 in audispd syslog plugin, "local6.* @@loghost:514" is in rsyslog.conf). The problem/question I have is whether it is possible to turn off rate-limiting for rsyslog *only for audit traffic*. Leaving aside that I need to tune the audit rules better, on heavily loaded servers the rsyslogd starts dropping most of the audit traffic due to the rate-limiting parameters. I know I can turn it off (or set it much higher) for all rsyslog, but is there any way to selectively set the rate limit by either source (audispd) or facility (local6)? I've just joined the rsyslog mailing list, if I fail here then I'll ask there, but I'm afraid that the answer will have something to do with using rsyslog v8, and I'm stuck with the RHEL7-provided v7.4.7. Any assistance/suggestions/leads are appreciated. Stephen