I implemented the 1 hour limitation to not allow any plugin user to overdrive the plugin and use their hosting’s cpu excessively (and afterwards complain to me that the plugin broke) – I already have customers that created 100+ importing rules and run them by hour basis. 
If you wish to get this feature, I can implement for you a payed custom plugin version, in which you will be able to run rules by minute basis. If you are interested, please contact me at my email address kisded@yahoo.com and we can discuss details about this.