Allows you to use the router with other providers like WE or Orange if the original Etisalat firmware is "locked".

Incorrect flashing will hard-brick the router. Also, OpenWrt may not fully support the ADSL modem (you would need a separate modem).

The ZTE ZXHN H108N has a history of CVEs (Common Vulnerabilities and Exposures). The most notable is the "Ping Tunneling" vulnerability and weak session management.