Hello,
Right now, the minimum amount of time after which the plugin can automatically run (even if you set an external cron job for this), is 1 hour).
I limited the auto-running of the plugin to 1 hour minimum right now, to not allow users to over-use their server’s resources, and complain afterwards that the plugin is not working for them – with hour based running, I still have some similar cases, when people create 500+ importing rules, each running each hour, which drains their server’s resources and they come to me afterwards asking for help.
If you know for sure that minute based running is fit for your server’s resources, I can implement minute based running in the plugin, just for you. I can make this feature available only for you (not to general public), because people don’t know how to use minute based running, and they will ask for support, when they over-used their server.
I can make a payed custom plugin update for you, to add this feature to it, only for you, only on your server. Also, you will get plugin updates afterwards, as normal.