If you keep this idea alive (and I hope you do!), you might consider shrinking the keyboard battery and designing its docking configuration so that it automatically charges from the main battery when stored in the laptop. A 3 month keyboard battery capacity seems sort of excessive when its mechanically part of a machine that charges daily.
I think one of the limitations to the keyboard concept you have is that it complicates using the laptop base as a stand for the screen in a tablet configuration. Outside of tablets with fully detachable keyboards (e.g. the Surface or the iPad pro), I don't think anybody has a good design for that. Was a touchscreen ever a consideration for stretch goals or design for expansion?
I think one of the limitations to the keyboard concept you have is that it complicates using the laptop base as a stand for the screen in a tablet configuration. Outside of tablets with fully detachable keyboards (e.g. the Surface or the iPad pro), I don't think anybody has a good design for that. Was a touchscreen ever a consideration for stretch goals or design for expansion?