Mitsubishi Head Unit Header Purpose

[pogz]

Hi, I'm in the process of upgrading my non android head unit (Xpander 2019 GLX, Philippine market) to the GLS variant android touchscreen (also Philippine market). I know that the 20 pin connector (top left of the image beside the fuse) is standard and I can outright just use my existing non android head unit and plug it in to the android variant.

But I wanted to check what are the other headers/ports/pins for?