Yes several people here have done mods like you are describing. It's not difficult to wire and fairly easy to program, but there's some tricky things you have to do to measure voltages and currents, mainly it's a matter of timing and filtering. Also you need to do some math in code to work out RMS data points.
You may want to use a MOSFET driver rather than trying to drive the MOSFET directly off one of the MCU's I/O pins. MOSFET gates have a good amount of capacitance and you want to avoid driving capacitive loads directly off an I/O pin. It's hard on the MCU and in extreme cases can cause spurious resets.