Not sure if this has been said but along with dressing the sides of the bar for burrs, you also need to dress the rails. The chain tends to run it down particularly at the base of the bar by the dogs and sometimes at the tips depending on the length of the bar. This what the bar dressing file...
There’s a distinction between “let it run” and “run it through.” I know Letting it run very well. I’ve had riggers who did not and watched me be violently sprung around. Luckily I’m pretty decent at bull riding.
That tracks. We’ve had tons of drought conditions in the last few years, and any of the long time local guys say it lines up with a bad drought from 12ish years ago. Hypoxylon doesn’t always kill right away, from my experience. It many cases it can take 5-10 years depending on the tree itself...
I was taught to say “run it through” when needing to run it through the system with no wraps. We also would not use the top cleat, as it would most often slip off in a negative rigging situation when it would flop in the slacking moment.
The 1st picture looks like it for sure. Indeed, it is an opportunistic fungus that takes advantage of a tree when stressed. From what I’ve been told, most susceptible trees have it and live with it, the tree’s natural defenses keeping it at bay to a small colony, until a stress event comes along...