The Intel ME still performs minor power management functions and minimal init functions via the BUP (BringUp) module.
For all intents and purposes, osboot-preinstalled X230 is 99% as free as a Libreboot system, and I would argue that it is equally secure.
However, the Libreboot X200 is also sold on the website, and Libreboot is fully endorsed by the Free Software Foundation.
There is also the GbE NVM (non-volatile memory) region, which configures the onboard ethernet chipset.
These configure the hardware, and the format is fully documented by datasheets.
In Libreboot there is a tool that I wrote called ich9gen, which can entirely generate ich9 ifd+gbe from scratch. This does not exist yet for sandy/ivy i think, but yes there is that --dump option in ifdtool.
By the way:
bincfg is a nice tool in coreboot, and you can write a spec file for that, based on intel datasheet, to generate gbe/ifd images. I actually have this on my todo list, as I've been studying it. The datasheets are very confusing especially for the Gbe NVM region, making it look like it's not even documented, but it is, poorly.
That's very good news. I thank you for all the work you've done on this.