here is maybe another way to find root hole.
create a ftp server on your machine.
create a user with name: images and password: images
in the root of the user images create folder cache
you can now place a "ota_update.zip" in that folder for late download to your o4x.
remember that file still needs to be signed
on you mobile, you can activate download of that ota_update.zip through hidden dialer menu(8435#*880#)
and select image updater and enter your ipadress of the pc with the ftp server. and press connect.
you will see the ota_update.zip as a filesize of X bytes and you can select it.
selecting it will download and reboot o4x, and enter recovery.
but for now it fails as it is not signed with LG sig.
but maybe a way to put updates on it, since recovery do not find external sdcard, and we cannot put them onto /cache ourselves.