As of the 6.9.2 release the plugin still includes an automated purge log event in the form of a daily WordPress cron job.
Use the Days to Keep Database Logs setting in the Global Settings module to control the amount of data to be kept. (Note the default value was changed from 14 to 60 days … another reason why the logs table may be bigger today then what you were used to in the past).
The setting allows you to specify 0 days which should result in an empty log once the purge log event kicks off …
Not perfect but it should work …
If your log is still keeping older records then what it should according to the setting described above or it just won’t empty using the method described above you may be running into a known bug.