Help identifying an oil leak in the crankcase valley?

Hello,
I’ve been chasing down an oil leak from somewhere in the crankcase valley. I Initially thought it was the oil filter housing gasket, as the oil pools behind and around that and r eventually leaves a film on the top of the gearbox and back of the heads. No runny drips or anything, but a fine layer of film that attracts dust and looks caked up. But it definitely pools in the little recesses of the valley right around the oil filter housing.
Today, during my oil change, I removed the filter housing for the second time, gave it another righteous cleaning, and replaced the gasket again. Torqued everything to spec. I cleaned around the valley, block, and gearbox. After going for a test drive, the oil is immediately back. So it’s not that.
I put my boroscope down there, and the majority of the wet areas seem to be around the “sensor for firing” (cam sensor?) part number 75177672, mostly on the right hand side, but there’s wetness around the one on the left hand side, too. The other area that has the most oil around it is the threaded plug on top of the block, directly behind the oil filter housing. Looks like a 14mm Allen, but I’d need a shallow key to get in there to try to tighten it to see if it’s loose, as it’s right under the edge of the heat exchanger hard pipes.
I verified that every part of the heat exchanger appears to be dry.

So does anyone have thoughts or suggestions? Do the “firing sensors” have a tendency to leak from their housings? I tried to get a 10mm on there to see if it was loose, but it’s either not a 10mm, or I couldn’t get a good approach angle. That said, I can still see the torque pen markings from the last time they were installed, and they’re all still lined up…

Looking forward to some help on this one!

Thanks,
Jeremy
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Some more pics from today before I do another cleanup and another startup to see if I can see where it’s coming from. I also confirmed with a mirror that the transmission lines under the heat exchanger are bone dry. I’m wondering if either of the braided lines for the transmission themselves could have a pinhole that’s spraying a fine mist of oil into the valley? I don’t see any other lines under there that carry engine oil… Is it possible it could be valve covers?

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