Unfortunately that near-100%-efficiency wasn't quite realised in practice, for several reasons. I think I can describe some of them without giving away anything commercially sensitive:

1. The spatial light modulator we used didn't give anything like the 180 degrees of phase rotation outlined there, which means that a large fraction of the light landing on it passed straight through.

2. Having only two phase states leads, as mentioned in that page, to a conjugate image with as much light in it as the one we actually want.

3. All that random noise does indeed average out nicely when you have many "subframes". But since there's no such thing as negative light, parts of the image that are meant to be black will inevitably end up something other than black. So there's a loss of contrast, which means that some of the light in the image isn't really doing you much good.

4. The optical design has a bunch of lenses and mirrors and things in it, and every surface is an opportunity to lose a little bit of light.

The actual optical efficiency figure was, let's say, somewhat less than 100%. (Also, for every frame we displayed we had to compute a lot of Fourier transforms, and the compute hardware takes power too. Which wouldn't matter for large mains-powered projectors, but is more of an issue when you're trying to make a small low-power device for mobile use.)

We had some next-generation technology in the works that would (if brought to completion) have fixed most of these issues and produced better efficiency along with better image quality -- but then we made the (very sensible) decision to get out of the picoprojection market completely.

Each of your points is very illuminating. It's such a nice idea that it's a shame it turned out not to be worth pursuing from a business point of view.

Perhaps some day somebody will take up those next-generation ideas!