The plugs require a well-lit magnifier or macro camera to read well, all the way to the bottom of the center ceramic. Complimentary info
here and
here.
How the plugs were used at the moment of engine shutdown is critical to the information they can provide. For example, if reading plugs for wide-open, the engine should be run wide-open for as long as possible (full 1/4-mile or whatever you can do) for maximum coloring on
clean plugs, then the engine cleanly shut-down
from that condition. Or, idle reading done after several minutes of fully-warmed idling and shut-down from that condition, and so on. In each case, clean plugs must be used to see the coloring and indicators.
Clean plugs, with clean shutdown from reading condition. I use several sets of plugs in a full tune for clear, good readings. There is no waste, as they are shelved for later replacement use. Cheap on-sale plugs are fine for
initial tuning, to get into the ball park. Your plugs appear to have seen low-load/idle before shutdown, else the oil and carbon would have burned-off (assuming optimal tuning) -or- your high-load tuning is excessively rich on some cylinders and oil is heavy enough to have not burned-off. Notice the concerns or confusion that pop-up if the plugs are not read for the condition.
On the surface, I see no obvious signs of detonation.
Mixture is questionable with mixed use, but not horrible in any general sense. Plug 1 appears to have a gasket leak. Perhaps installation torque. Plug 5 is a combination of fuel and oil fouling. Plug 6 has more sheen, and appears to be more oil fouling. Timing is again difficult with mixed use, but appears between optimal to slightly over-advanced in
certain unknown areas. Heat range is OK to a bit cold (don't change that yet!), again not knowing conditions for the read. All-in-all, not bad, and limiting oil to the rear plugs would help generally, with some fresh new reads to confirm specific operating areas.
As previously mentioned, purging the vapors overboard (instead of through PCV and into the engine) temporarily could help confirm the oil source and conditions for it. The ECM should compensate for that condition, but keep an eye on the tune for it. Hope that helps.
[EDIT] Check your catch can baffling. If minimal, you might consider stuffing more material in (commonly stainless steel or copper dish scrubber pads), or adding a large paper element filter after the catch can to help remove vapor mist or particles.