The pic's of your plugs do show signs of an oiling issue.
Which holes did they come out of? Cylinder numbers?
The plugs that look black and gummy are the offenders.
Start with the top end and work your way down.
My guess at this point is rings, that's a lot of cylinder pressure to deal with.
The ones in the vertical are 1-3-5-7 bottom to top, 1 and 5 definitely corresponding with the dry/wet compression test I did. #1 gained 20psi and #5 gained 40psi.