and you can minimize ME in Sandy and Ivy Bridge, using ME_Cleaner?
edit: according to sounds' comment* in HN (2016), The ME is purportedly placed in "recovery" mode
[*] https://news.ycombinator.com/item?id=13056997
https://libreboot.org/docs/hardware/gm45_remove_me.html
after that it's impossible though.
But very stable, I am looking to flash my X220 soon for what it's worth.