Does this formula work for I2C sensors?
Yes, I'am using only I2C ones.
The "Read_MR - Measurement Request" might not work. A test with a logic analyzer to confirm that it works for the ESP8266 is needed. It does not work for a Arduino Uno or Mega: https://github.com/arduino/ArduinoCore-avr/issues/421.
The Read_MR command would be:
Wire.requestFrom( i2c_address, 0); but since no one uses that, it might not be implemented in the Wire library.
There is no need to read 16 bytes, 2 is enough.
There are typos in calculation:
wrong: (((100 * (Fbyte * 256 * Sbyte)-81915) * 200)/163838)/9
correct: (((100 * ( Fbyte * 256+Sbyte)-81915) * 200)/16383)/9
for 10 bar: (((100 * (Fbyte * 256+Sbyte)-81915) * 100)/16383)/9