You have not provided enough information to give an answer.
Watts = voltage*voltage/coil resistance.
You only provided us the voltage. Since we don't know the resistance we can't calculate the wattage. You need to find the resistance of the topper you are using. Since the original MVP had no multi meter that might prove difficult.
What I would do is get the new one, set it to 4.6 volts and if it vapes the same, then press the P and U keys simultaneously and the first set of numbers will be your coil resistance.
Now you can calclulate your wattage and it will tell you what to set the MVP to in variable wattage mode.