There is a procedure to move the main storage partition to the Android /data partition using a couple of commands in SSH:
mkdir -p /media/data
mount /dev/data /media/data
mkdir /media/data/coreelec_storage
systemctl stop kodi
rsync -ah --info=progress2 /storage/ /media/data/coreelec_storage/
umount /media/data
mf
vi /flash/config.ini
# add this line at the end of the file
coreelec='quiet toram disk=FOLDER=/dev/data'
# and reboot
# check everything was done correctly with command
mount
# before
# /dev/sda1 on /flash type vfat (ro,.....)
# /dev/sda2 on /storage type ext4 (rw,noatime)
# after
# /dev/sda1 on /flash type vfat (ro,,.....)
# /dev/data on /storage type ext4 (rw,noatime,resgid=1065)
# I also add this line in /storage/.config/autostart.sh
# to unmount storage partition from USB stick
mountpoint -q /media/STORAGE && umount /media/STORAGE
reference: Homatics Box R 4K Plus - #278 by vpeter