It feels reassuring that you can actually get access and read the assembly of the IME now, thanks to https://github.com/ptresearch/unME11. For instance using the the Gigabrix-BSi5ha-6200 IME Firmware update archive:

1. Download and unzip the Gigabrix-BSi5ha-6200 IME update archive (http://download.gigabyte.us/FileList/BIOS/brix_bios_bsi5-h-a...). Use F5_BIOS/image.bin from that archive.

2. Start "python unME11.py image.bin"

3. The uncompressed modules are located in image/00004000.FTPR/* after that

4. You can i.e. load image/00004000.FTPR/kernel.mod in IDA using 80486 in 32bit real-mode or use "objdump -m i386 -b binary -D kernel.mod --adjust-vma=0x80000" with entry point being 0x80000 or "objdump -m i386 -b binary -D bup.mod --adjust-vma=0x2d000" with entry point being 0x2D04C