I appreciate your input DG, even though it was so long-winded that I need to go lay down now.

One thing that your experience of the lack of problems brings to mind for me is that a lot of people who have engine issues have a knee jerk reaction to blame the danged 10 %.
A similar reaction was even more vehement back in the days of the advent of unleaded fuel. Remember all of the tales of a single tankful of leaded gas in an unleaded engine, or vise versa would destroy your engine?
Carl