no Dolby Vision for projectors
We have to remember how controlling Dolby is. With a DV TV, no user adjustments are allowed while watching DV content. Dolby is also the inventor of PQ with its absolute levels. (Optimizing the TV signal for only 12 bits, when there was no need to optimize it. A 16 bit 422 4k@ 24 fps fits within the HDMI 1.4 bandwidth).
So with projectors, with no guarantee of absolute brightness, it may be a non-starter for Dolby. Yet with DV movie theaters, they obviously have no issue with a 108 NIT max peak output.
IMHO, this is just a red herring, as one could have user inputs to state what max output you have, or a projector vendor could have an inexpensive sensor that measured peak brightness during a setup mode.
As to the advantage of dynamic metadata, (IMHO) the advantage is totally overblown. Any projector with dynamic iris now must be calculating on-the-fly the same peak and average white level per frame that is in the DV metadata. And then you can guarantee it's accurate.
So to me, the only real advantage to DV is 12 bit signals with no banding.