It should take care of itself. It only keeps the info for a short time. I've ran a lot of flash installations over the years including 2.x.x all the way through the development cycle and have never had an issue with the two tarballs getting too big, they will be pruned by the system automatically. Having only a few MB free at any one time is normal. The only reason they exist at all is in case of a reboot to restore recent logs to /ram/var/log immediately after /ram is mounted via TMPFS, your logs and graphs are all available to you at all times in /ram. If the machine is always up, /var/log_compressed is irrelevant. It is only there to restore recent info on bootup and to store the most recent info upon proper shutdown or once an hour to minimize flash drive writes. You can lose up to an hour of logs on power failure but never equal or greater than an hour.
Why are you so concerned with keeping your logs so pruned to where there is little left? It should be very low priority. Many people are the opposite, they bemoan the rather short cycle where logs are retained on flash installs. I send mine to syslog on my central home server in case I ever want to look back at anything more than a few days old.
I guess I am trying to figure out why you see this as a problem.
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