grub and bcache

Is the underlying bdev bcache format such that bios/grub won't be able to boot off it?

Or to put it another way, I am wondering whether I can get away with:

/dev/sd[ab]
 md0
  bcache
   lvm
    lv-root
    lv-boot

like I do now without bcache and have grub find the lv-boot, or if I need a separate md device to hold /boot like:

/dev/sd[ab]
  md0
    boot
  md1
    bcache
      lvm
        lv-root
        lv-boot

thanks

James