.Thats a another long term goal for me
Of course if you change the loop power voltage, then you must scale the sense resistor at the Arduino analog input pin. For example, if you were using a 24V loop voltage, you would use a 1200 ohm resistor between ground and the Arduino input (which would also be the sensor - side). The 1200 ohms would develop 5V when in a 24V loop with 20mA flowing (Ohm's Law again).
I do want to protect against such errors and mistakes!