Yeah, just usb 2.0, that why I was hoping you weren’t looking for a screen. Not that a screen couldn’t be done, I understand there are chips to handle compressed video over usb 2.0 speeds, but it would be more complicated & limited. Also, there are power restrictions with the stock midplate at least.
From the github you saw that the middle 3 connectors intended for the touchpad are i2c rather than usb? So you’d probably want to use a different connector. The EC (embedded controller) where the i2c is fed to is open source, but usb is just much easier.
Here is an example of someone creating a module for next to the touchpad and using one of the unused usb connectors. E-Paper module to replace spacers in palm rest