I've had my 10 units for months. I just tried setting them up tonight, and haven't been able to get the actual entities work yet.
You can flash firmware configured for 1) Home Assistant, or 2) SmartThings. The ESPHome driver in HPM has specific support for this device.
When using the EP1 in HA-mode, the ESPHome driver in HE can communicate, but no entities appear.
When using the EP1 in ST-mode, the ESPHome driver cannot communicate, but interestingly-enough the EP1 then has its own UI you can access, like Tasmota.
If I figure this out, I'll report back.
btw temp and illuminance do report right out the box.