Beginner Questions About SmartThings Events (Grovestreams)

I recently added a SmartThings Hub and a bunch of Aeon Labs powerstrips and plugs. I’d like to integrate with GroveStreams to do comprehensive power and energy monitoring. I have the SmartApp and GroveStreams setup and when events do fire they seem to be logged in GroveStreams. The problem I’m having is the frequency. It seems that unless I hit the “Refresh” button in the App energy reading events don’t fire. If I turn one of hte Aeon Labs SmartSwitch 6’s on/off the event shows up in GroveStreams, but I can’t get any energy/power readings either the mobile app or GroveStreams.

My question is, how often do these devices send state information? Is this something configurable? Is this something I would have to author a custom device type for?