Building mesh with Keenetic Giga

Stayer

Hi.
I have Keenetic Giga III as my main router which is connected to the ISP. I want to extend WiFi coverage with NWA1123-ACv2 which is connected to the Giga III with a wire and PoE injector. AFAIK this can easily be done with another Keenetic OS based device: https://help.keenetic.com/hc/en-us/articles/360002155079-Wi-Fi-system?utm_campaign=3.05.C.2.0-1&utm_content=controlpanel/wifisystem&utm_medium=ui_notes&utm_source=webhelp

Is it possible to do so with a NWA1123-ACv2 (acting like a Repeater and listed in Keenetic WiFi system list) ? 
Main reason to use the Nebula device is that it's PoE powered.

Greenlight

It seems the Mesh can be only established within products of the same brand. For each vendor has their proprietary method to establish connections between APs. In the Keenetic article it also mentioned the router can only manage additional "Keenetic" devices.

The mesh function on Nebula is called "smart mesh",you can use it to connect two NWA1123ACv2 wirelessly. I remember it's also a proprietary function, so only Zyxel products can form up a mesh system.