Support for Easybox 904 LTE

I have never used luci no idea if it works.
Did you mean "at the moment '00' and signal power is 0" in luci

Modifie the /etc/config/wireless via SSH and reboot the wifi via: /etc/init.d/rt3883 boot
see the /etc/init.d/rt3883 for single commands.
Some values can be change with the old iwconfig and iwpriv commands.
@kovs should correct me, but he background are it based on a very old driver time before using the default nl80211 connection of the linuxkernel.

yes it is normal flash_eraseall do not exist anymore.
use:

flash_erase /dev/mtd0 0x0 0x2
nandwrite -p /dev/mtd0 u-boot.lq

instead

The combination of @pc2005 patches

and
software flow offloading
brings 88Mbit/s from 94Mbit/s VDSL speed. (no SMP support, i use the FXS ports)

At the moment it is the only solution for VVDSL (up to profile 30a) and Telefon support i can not see that there are somthing change in the next future.
An other thing are these devices second hand are really cheap in Germany.

I do it long time too but i more and more understand why openwrt official support only wifi and ethernet.
Every time when i make an build somthing else does not correct work

At the moment the biggest problem are SQM (using the tc command) in combination with the Wifi driver reboot the devices.
(see here: SQM reboot my Router (Easybox 904xDSL))