Exactly right. The fuel dilution IN THE RING PACK is double or more what you’d measure in the pan sample.Gasoline is the main culprit of the ring lands getting stuck because it fills up with carbon. Gasoline, especially low-octane fuel, is cheap for a reason: it contains very little to no detergents. Personally, I use a fuel system cleaner twice between oil changes, maybe more often. It seems to help. I would definitely keep using Valvoline R&P and also use some fuel system cleaner, maybe Techron High Mileage or something similar. Red Line SI-1 is very good. PEA has a tendency to clean those carbon deposits.
SL1 is my favorite and has been for years. There’s an ebay seller that has a good price on it.
I switched to V-power nitro not because I needed the octane for my TGDI engine (although it doesn’t hurt) but because it has the best detergent package of a mass market fuel in my area and is Top Tier certified (much harder to find since Circle K dominates my area and they are no longer affiliated with Shell and circle K fuels are NOT Top Tier anymore).