I wonder if the idea has been ever considered at Fairphone. I’m currently thinking of buying a phone with E-ink screen. Ideally I would like to have a fully functional smartphone, ie. good camera, LTE connectivity, perhaps dual sim. Fairphone seems to be ideally suited with the modular construction - people could choose color or e-ink screen upon purhase but change it easily if they change their mind.
Hisense recently released A5 which looks awesome but unfortunately it lacks the LTE bands I need. There’s also Onyx’ e-ink phone on the horizon, but no detials yet.