iGO uses the following folders / lines :
- HD resolution : 1024_768 / m5 & m6 => device's resolution must be between these values
- FHD resolution : 800_480 / m3 & m4 => half of device's resolution must be between these values
- QHD resolution : 1024_768 / m5 & m6 => half of device's resolution must be between these values

For your device, you should :
- sys.txt :
[rawdisplay]
driver=engine
screen_xy="auto"
- multimode.ini
m3=768..1300,400..600,"800_480" ; ( 768 < 2400/2 < 1300 , 400 < 1080/2 < 600 )
m4=480..600,700..1300,"800_480" ; ( 480 < 1080/2 < 600,700 < 2400/2 < 1300 )