You can put any tank or dripper you like on it, and it will work so long as the coil value is greater than .1Ω, according to the description. "Self Adjusting" is a fancy way of saying "you can't adjust it." I am having a hard time understanding how it works from the description. Apparently the Facetank has only Ni coils available, which would mean the machine has TC circuitry. Presumably if you put something with a resistance wire coil on it, it would recognize this and bump to wattage mode. I have no idea what wattage the machine actually puts out but, if you're are really vaping 21mg nic on a .1Ω or .4Ω coil, I don't think it will be 100W. That would paralyze a charging rhinoceros.
In any event, if you are satisfied with the vape, and it's keeping you off the sticks, then you're doing it right. Vape on!