I have been building two stroke motors since the late 1960s.  I have not seen any new technology in castor oil in the last 40 years and I have still not found any two-stroke lubricant that does a better job than castor oil.  Castor oil has some unique properties that petroleum and synthetics do not possess. 

Dick Lechene founder of Maxima Lubricants told me many years ago that all of the US oil companies get their castor from the same two or three barges that comes to the US each year.  How the different oil companies press it (filter it) and the additives each company uses that improve its "mix-ability" with gasoline is basic difference from one two-stroke castor oil to the next 

The fuel/oil ratio DEPENDS upon how the engine is operated.  A two-stroke engine that only runs at an idle will receive adequate lubrication at 80:1 to 100:1.  Large two-stroke engines (100cc to 500cc) running ONLY at wide-open throttle needs fuel/oil ratios in the 10:1 to 20:1 range.  Some model air planes engines run fuel/oil ratios of less than 10:1. 

It becomes obvious that one has to choose whether we want to mix enough oil in our fuel for the most severe mode of engine operation or go with less oil and limit the amount of time that we can spend at each brief blast of wide open throttle.  An engine needs ratios below 20:1 when the throttle is wide open and the RPM are high for more than about 3 to 5 seconds.