Wattage is controlled by Voltage. Voltage isn't necessarily controlled by Wattage, but You can't have one with out the other. Where there is Voltage, there is Wattage, Resistance, and Current. Wattage just calculates your voltage for you depending on the resistance of the coil. When you're using voltage controls you're manipulating the formula, Watts= Volts^squared / Resistance... Your chip is using an algorithm with the formula Volts= Square root(Watts X Resistance) to calculate the voltage for you.
If you're using different resistances, you might want to use VW, until you get familiar with the sweet spot of all your liquids on the different coils.
It sounds like you're having wicking issues. I can't use a lot of the flavors I love with anything but drip atomizers..and even still, they can gunk up badly. I got a friend an MVP the other day, and I recommended a voltage to move towards after starting from 3.3 Volts. He actually ended up staying on 3.3 Volts with a 2.1 dual coil iclear16(don't know if that's still the case). 3.3 Volts with 2.1 Ohms is 5.2 Watts, but since it was a dual coil, that heat is distributed 4 times as much as a single coil, equaling dramatically cooler and less noticeable vapor production. You don't have to be at the bottom, middle, or top of the scale. Find out what works for you.