Look at both sides of the fire ring on the head gaskets. That will tell you if it’s passing coolant. There is definitely some weird distribution, and possibly steam cleaning. I thought your mechanic verified a wiped lobe on the cam?
I'll post some pictures of the head gasket. Well the tech thought it was bad lifters at first. Mainly because, they would clater when started up cold along with the tick when the engine would shutter.
After pulling the intake to replace the lifters, he didn't like the wear pattern on the cam, and that lead him to drain the oil and cut open the filter which revealed the glitter in the oil. He didn't say we lost a lobe we just assumed by all the glitter.