@killerbee you're welcome 🙂
Worked kind of. Its important that you first create a folder in the user-data/xenial folder
I named it SDCARD and then the mount command is:
sudo mount -B /media/phablet/ED34-76D7/ ~/.local/share/libertine-container/user-data/xenial/SDCARD
Now i can access the data from libertine apps 😉
Well from that link @UniSuperBox shared it looks like the Ubuntu/Mozilla devs for ARMHF hardware are at last aware of the issue and working on it for those architectures.