What type of power supply to use for HLW8012 Energy Monitor

[Eldi4]

Hello there, i've been puzzled on what power supply to use for HLW8012 which is single phase energy monitor, it must connected to AC Grid Line directly to measure the RMS Voltage,Current, and Power. So it was impossible for the IC to get isolated from AC Line.
The HLW8012 will interface to my MCU with PC817 optocoupler, because the output frequency is not that high, probably just 10kHz max and because my MCU was powered with isolated power supply.
So i've been puzzled on the power supply to use for HLW8012, should i use transformerless power supply or normal SMPS?.
Because SMPS is isolated, powering HLW8012 will make it looped to AC Line once again, is it okay to do so?.
Or should i use transformerless power supply instead?.
For me, the cost for both solution (smps or transformerless) is the same, im about to use SMPS but not sure what would happen if the load is not isolated from AC Line.