using a magnifying lens, type fresnel, like this one:
costs only 5,- euro.
we can use a tablet like Sony Z3 tablet compact or smartphone like Sony Z2
(with native Playstation Remote Play + Fligh Simulation (WarTHunder) + Headtracker),
bring the display very close to our face while using the magnifying lens to avoid crossing eyes,
having 2D full HD working, in none Side-By-Side.
so we can try to build something from scratch or modify a durovis dive 5 or durovis dive 7.
so we can have today, what cmoar wants to bring out anytime in a commercial version, the 2D mono lense.
this will be a good base for PC based game streaming too.