Need some opinions on where to go from here...
Well I found this upon taking a quick look at the cap
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Looks like bad rotor/cap phasing.
Also make sure the rotor is pushed down all the way.
Even your average good sealing cylinder will lend some leakage to the crankcase when doing a leak down test via ring gaps.
The air is going somewhere, be it head gasket or rings.. both will enter the crank case or neighboring cylinder.. so remove the rocker shaft and pull the plug on the cyl next to it and put your finger over the plug hole to feel for pressure build.
One thing is for sure is if it's not just a valve hung open due to maladjustment.. its gonna a need to come back apart.
The cylinders that are clean are burning the fuel well... while the others are not.
Bad needle and seat can wash out rings and flood cyls making them extremely rich and blackened plugs as well. You checked the lash and say it didn't really change, so bad lobe seems less likely