seafoam is thin. I would expect it to wash down past the rings while sitting and would not be alarmed by this. The result you are getting does not indicate that you have a problem. Adding to that, one instance of a different consumption pattern does not indicate that you have a problem. Consistent patterns over time are where your better diagnosis will come from.
Compression test, with and without a tsp of oil, will tell you what's going on. The plugs themselves look great, with some potential deposits from fuel additives. If you want, half a can of seafoam in the oil and a can in the gas will be fine. I've driven many full OCIs with a half-can of seafoam in a sump that size, and for nice slow cleaning it helped.