Some mods don't have a wattage setting for TC, just temp setting. I use Kanger mods exclusively, and there is no wattage setting in TC, it doesn't matter if I set it to 5 watts or 160 watts, it still functions the same, some other brands are the same, depends on who makes them.
Kanger says the initial wattage depends on the coil resistance, I did read somewhere that the initial surge is at a specified voltage which would make sense. Whether that is at 3.3 or 3.7 Kanger isn't saying, or maybe it is higher than that I don't know. Some people say the initial surge is at max watts the mod will go, but I find that hard to believe since my .7 coils would burn the cotton using 160w, even if it only lasted a fraction of a second.