That first video behavior is the exact same as mine when my (+t) throttle stop and tps was mis-adjusted. IIRC I opened the blade prop screw like a quarter turn or two more than the closed tps switch spec and it helped considerably. Have you started by setting the throttle stop/tps to green book spec? got the feeler blades out? Winging it doesn't work well.
What it looks like to me is lh is making the fuel rich during the pull as per usual, then when you tip-out the throttle the lack of air and too much fuel kill/almost kill it.
Is the MAF/AMM pre turbo?
we have checked and adjusted the throttle body to greenbook specs, it's also been through multiple throttle bodies and tps I've the last couple years while chasing this issue.
the maf is pre turbo and I have added 2 90 bends aswell cause I read the 90 bends help with air velocity or something along those lines