I know almost nothing, but I would think just like our bikes do now. It's not really an automatic driven by fluid friction. It uses a solid clutch connection.
With that said, I have no idea how you start from 0 without some sort of slippage. This is a learning curve for me. Look forward to trying one out.
Let me add: I believe that I read that you may want to pick the manual mode while in the mountains and pick/paddle your gear of choice.