That plug features a CSE7766 for power monitoring which is/should be more accurate as the HLW8012 mentioned in other plugs so far. 
Beside also esp inside so full ownership can be taken and the thing should be future proof even years after the vendor filed for bankruptcy 
They used to have CSE7766 but downgraded to a HLW8032 last year 
That heavily depends on how the device actually is calculating the energy used. Often the device just polls the sensor every 
seconds and does a simple integral. If the load is resistive this probably gets the job done but if the is high and the power factor low the calculate energy can be quite off 
Now in case a manufacture ships a device like that with limited or buggy *ware you can change that behavior (and make it more accurate*) in case it has a esp inside 
On the other hand if it is a “black box” plug (
) there is not much to do beside accept it or maybe use a work’a’round in HA to limit the damage 
*best is usual a high esphome internal update interval (maybe 0.1s) for calculating the energy but at the same time a slightly lower/throttled interval for ha (for example 1 or 2s) to don’t bend the server to it’s knees with 50 plugs hammering in 
