Purpose of voltage_divider and current_resistor

I have several Gosund SP1’s which I have calibrated based on the great tutorial of @frenck available at Calibrating an ESPHome flashed power plug » Frenck.dev

I have always wondered myself why the voltage reading of the sensors (around 750 volts) was so extremely off from reality (around 235 volts). I went through the yaml created by Frenck and noticed the voltage_divider value wasn’t set and thus defaults to 2351 whereas several posts on internet refer to the value of 871.

My question is now: is it correct to assume that the wrong voltage divider leads to those high voltage values? And second question: if I apply a calibrate_linear filter would that solve the issue in the same fashion as setting the correct voltage divider value?

Would a calibrated_linear filter not be an overkill, the lower and upper limit of the grid power fluctuation is not that great.
Personally I have several Gosunds running in the house and well did calibrate them the lambda return value with the voltage readings of the P1 grid module readings then i placed them through the house.

snippet of one of mine SP1 too:

      name: "${plug_name} - Volt"
      device_class: "voltage"
      state_class: "measurement"
      unit_of_measurement: V
      accuracy_decimals: 1
#      icon: mdi:flash-outline
        - lambda: return x * 2.34245;

the other has a value of 2.3872 to correct it

The other Gosunds are SP211 and they have another chip in them so the correction value would not help you