Are Other Halves stack-able? No, I think? The connectors would be wearing off pretty quickly, I fear...
Is e-ink screen Other Half possible at all? As in, would e-ink screen be recognised by OS as second display? I guess I should be asking Jolla if they plan to release a phone where first display is e-ink
It's just... Backcover for the sake of physical stability, and nothing else, seems to be such a lame use of space...
Another idea for electricity-using Other Half: combine TOHKBD with Light-emitting OH. Or would it be too bulky-and-fragile-and-expensive (and not-working), too?