You can’t add any more stereo channels (or remove the existing ones), but you can link channels together with the “ganging” function.
You can have up to 8 gangs, and each gang can have up to 8 members. If you link everything except the pan controls it will act as a stereo channel (except for when you PFL it, as you’ll only get one side unless you use additive PFL).
There is also a trick by using a group bus. You can assign an external steeo input paur and will work almost the same as a normal input. You will miss the gate dynamics. And off course it costs 2 busses….
For small shows I use this when I really need a stereo fader in stead of a ganged one.
We use the ganging and it works well.
This was my first digital mixer, so excuse me if this is obvious, but I originally put both channels on the surface – the sliders move together, it looks cool, but wastes space.
I figured out quickly that I only needed to have one visible, and the other one stays ganged even though you don’t see it.