Do you run a data logger? Would be interesting to see rpm vs wheel speed. Repetitive dropping valves sounds like an over rev issue.
Lowering the Rev limiter wouldn't hurt. I can't see where an off road truck needs to be pinned at 8k+
Remember the asian OG Ginsu knife guy?
He'd chop onions at a high rate of speed saying " chop, chop, chop. Back and forth, back and forth. No cry. Know why? No time cry! As fast as he was chopping.
Might have been what we were smoking back then... but that dude was hilarious 😂