> I can imagine some form of folding of attachment mechanism that converts a single screen laptop to dual or triple screen.
Razer is working on exactly this: https://www.razer.com/project-valerie
Razer is working on exactly this: https://www.razer.com/project-valerie
EDIT: Another alternative would be to be able to slide the main screen halfway to the side thus allowing a second screen next to it for a dual screen setup.