helios 4 stats according to google for the 240v 1000 watts per outlet 4k max total 30a input 20a out max the e720 is like 750watts (720+ watts to their sheets but lets round up to 750 for safety) with an amp draw of 3.4amps at 240v input putting you well below the 20a max. output of the helios with room to spare. So this should put you right in the range for optimal efficiency from the controller. its not too low or too high of usage. Which for most items is the sweet spot.
varies from component to component, but the theory is there.
which is kind of easier to display if we look at the efficiency graphs from PC power supplies as just a visual aid to the concept. So your good to go!