Brighter projectors would certainly help, but only if they can expand contrast ratios. I haven't read about projectors using the perceptual tricks you describe

Brighter projectors would certainly help, but only if they can expand contrast ratios. I haven't read about projectors using the perceptual tricks you described: it seems like POV-based approaches would have a distracting strobe effect? Just like with CMYK prints, if you want to render something "out of gamut" (colors that aren't representable with the display), you need a different display. This is typically done in print by adding spot colors to the color separations. Similarly, displays that add color emitters that aren't just blue, red, and green can render beyond sRGB. I believe some "quantum dot" displays have yellow and pink emitters, for example.