I think the child devices are a carryover from the porting from SmartThings. They don't do anything on HE and are not needed to be frank. You can use any of the readings in a RM rule. There's no need here for the child devices. Configure just sends parameters of the driver to the device. You only need to click it once.
I get no errors, and I can set mine to refresh every second if I want, but I leave mine at 5 seconds. My HEM is on a separate HE hub by itself. Keep in mind that it will take time for it to report (also don't forget to repair your Z-Wave network). I have somtimes had to exclude and join the v1 HEMs a few times before the worked right. Older chips. Kind of a pain to join properly. Factory reset by holding in the button while you insert the power. Keep it held in for 10 seconds. Then do a general exclusion. Do wait 30 seconds between each step. Trying to reset, exclude and then join too quickly will result in issues.
Here's my config that I use just for monitoring.
