I had specifically switched to using higher octane (mostly 89) more frequently to see if it made a difference in this 2nd UOA. I frankly wasn't anticipating a change, but since fuel dilution went down I was very interested in seeing everyone's feedback! I feel like throttle response improved slightly along with a smoother idle but I assumed it was very likely a placebo effect.
I appreciate all the discussion here about it and am now having a hard time deciding if I should just continue with 89. I know it would be cheaper to just change the oil even earlier (or run it as is) but I would rather just avoid the fuel dilution altogether if it is as simple as using 89. With the relatively high MPG and low miles I average each year, the additional cost for higher octane is pretty small for less fuel dilution.