Were you able to get this working? I have the exact same setup as you and I think I have it working.
I spoke with Aeotec support and unfortunately you can’t have the HEM in net meter mode and still get energy totals i.e. kWh sent to and from the grid.
To get around this, I created some integration sensors based on the instantaneous power measurements as seen in this post.
I’m just waiting to confirm that the kWh calculated by HA match the HEM, but to do that I need to wait for the sun to go down. 
I can post my exact configuration if you are interested.