Additional info:
I was previously having problems with porosity in ground, clean A36 steel. NOT galvanized anything. I solved the porosity issue by using stainless 309 filler. I was also having some success using going slow and jamming as much ER70S2 filler as I could manage into the weld. However even the steel welds have a dull grey appearance that can be wire brushed to a nice shine.
I did try cleaning settings between 20 - 80%. 20% gave me more black goo and 80% gave me a giant ball on the tungsten and no penetration, as expected.
I think I'm better than halfway thru the 55cf tank of gas. So soon enough I'll have a fresh tank of gas to try.