Try using one of your fill screws from the spares bag on your plus. Many people tried a different screw and it stopped the leaking. O-ring or not.Yeah I still want one, just not sure when that will happen. This one is very tempting to me, I really like the tight draw. With the KFL lite plus's I could live with those, the air flow screw was just a bit irritating, I preferred the original design. With the plus the fill screw 0-ring also always fails and leaks also. This one just looks like a better first choice for me.
KAS