Emeter uses different code path for the cli and for features, causing missing information such as the voltage and the current introduced in #1281.
$ kasa --host foo emeter
== Energy ==
Current: None A
Voltage: None V
Power: 2.727 W
Total consumption: 0.063 kWh
Today: 0.063 kWh
This month: 1.795 kWh
vs.
$ kasa --host foo
== Primary features ==
State (state): True
Current consumption (current_consumption): 2.8 W
Voltage (voltage): 230.8 V
Current (current): 0.04 A