Hm, could that be fixed by covering it with a "privacy screen" (used to cover computer screens, basically a bunch of tiny parallel tubes (all-angle) or grooves

Hm, could that be fixed by covering it with a "privacy screen" (used to cover computer screens, basically a bunch of tiny parallel tubes (all-angle) or grooves (one-axis, probably best for this))? Then maybe a blur on top of that to increase the viewing angle again (though that might cut the light too much since it's not an active emitter)?