Wouldn't that community better served by a "libre" (1) USB braille keyboard, that could be hooked to anything that has usb, and something like that as a display (I dont' know which technology those kind of displays need for cabling)
But the user would still need to carry around that keyboard plus a "standard" computer (I guess it could be a tablet).
On the flip side a "braille EOMA housing" with an EOMA A20 card inside could be turned into a "dumb USB braille keyboard" via the A20's OTG port.
Stefan