3) Place ./grub2.img onto windows boot partition and configure BCD with bcdedit.exe under Windows to load the file as a BOOTSECTOR application.
It turns out that ./grun2.img can be larger than 512 bytes. BOOTMGR will load it just fine. Now, to be honest, the second step is just annoying. Do you have a format option for grub2-mkimage that would automatically include lnxboot.img? It would make the whole process so much smoother and more logical. Just a suggestion.