I have also wondered about AUTO-RX and super small engines, but since my briggs-stratton engine is a 5hp push mower with a ½ qt capacity I said let’s try LC instead. I wish I had the before pictures, clear oil, but after adding 2oz of LC which corresponds to the 4OZ per qt of oil for the flush phase I ran the engine for three 45 minute sessions (the time it takes to cut a ¼ acre of grass) After the first session, the oil darkened so I added 2oz more of LC just for the heck of it. After the second run, the oil turned pitch black and after the third session I changed it out. I will try to post pictures as to what the contaminants in the oil looked like because on top of having a black oil, I had very fine black sediments (carbon deposits) settle to the bottom of used oil. The old oil was M1 10W30, now that I have the new oil in with 2oz of LC, I will take pictures one more time just to compare and see what will happen to the oil.
Interesting to note that the before adding LC, oil looked normal with very minor usage.