You can disble the cronjob based approach. Inside the plugin settings > cache tab there is an optrion to disable the scheduler which uses cronjob.
Ah, it’s called ‘queue’ here and I was looking for ‘cron’. That’s why I couldn’t find it!
While I’m at it, may I offer a comment on the legend:
By default this plugin purge the cache after 10 seconds from the purging action, to avoid a high number of purge requests in case of multiple events triggered by third party plugins. This is done using a classic WordPress scheduled event. If you notice any errors regarding the scheduled intervals, you can deactivate this mode by enabling this option.
The notion of a 10-second delay only covers the case of wp-cron.php. On sites where this is disabled for performance reasons (a common scenario) and crontab and WP-CLI are used instead, the purge is delayed to whatever time is scheduled in the crontab. So there’s probably room for the wording here to be improved.