Full dmesg after boot with acpi_osi=! acpi_osi=‘Windows 2009’ into xorg ran by integrated GPU alone, with bumblebee service disabled:
https://my.mixtape.moe/vvfhtl.zip
The lines up to the last with 7.15… timestamp are what’s there immediately after boot.
The lines with 106.88… timestamps are what’s added when I manually start bumblebee service ( service bumblebeed start ).
About 20-30 seconds after performing that command, the fan started to spin at maximum speed and is still doing it.