To sum up for whoever in the future:
BIOS 3.06 is broken in some way
92HD95B is a piece of crap.
When the computer plays only a movie then audio is kinda fine, so when battery saving is needed then simply run this script to allow states, below C3:
#!/bin/bash
pkexec su -c "echo 9 > /sys/kernel/debug/pmc_core/ltr_ignore"
On AC it doesn’t matter anyway.
Power consumption went from ~12W to ~8W, which is fine since I have animated wallpaper, gen 4 SSD, and an HDMI expansion card.
I really want to see a decent audio amp in the expansion slot in the future.