I dunno. A folding phone will probably be too fat. Typing on a second screen probably can't be much different than just using a larger phone like a Note 8 or some other 6 inch phone. Might be OK if in landscape. But still missing that tactile sense which is a very important feature of HWKB. I remember hearing about screens that could make little bumps on the surface to give a tactile sense. Maybe that could be made to work. Otherwise, If I can't have a HWKB I would prefer to enter information telepathically!