Ramlog postrotate interfering with systemd rsyslog.service

Ramlog.service postrotate will execute a cat from /var/log.hdd directory to /var/log directory while rsyslog.service is always outputting stuffs in the background to /var/log directory. This in general has no problem except for some files which are mostly preoccupied with output from rsyslog during logrotate activation, namely syslog and a varieties of journals entries. I have found some of these postrotate failures with cryptic messages as write errors from cat and corresponding rsyslogd omfile module stating lost messages. I suspect two independent processes competing to send output to same files hence causing these errors. I don't know enough of detail but I think there needs to be some coordination between rsyslog and that postrotate function in ramlog to avoid this conflict.