Comment by shagie
Spitballing, but a HDR digital camera could be designed with a beamsplitter similar to that of the 3CCD ( https://en.wikipedia.org/wiki/Three-CCD_camera ) designs that projects to an assembly with only a sensor behind it, another to an assembly that has a 4 stop neutral density and sensor, and another to an assembly that has an 8 stop neutral density and and sensor.
This way it wouldn't suffer from any parallax issues and sensor images should then also line up to allow it to be reconstructed from the multiple sources.
That said... HDR images can be "bland" with it being washed out. It would probably take a bit more post processing work to get the image both high dynamic range and providing the dynamism of what those old Saturn V launches showed.
Back in the day, Fuji had a sensor in which half the pixels had a 2-stop neutral density filter, IIRC. It was a 12MP sensor, with an effective resolution a bit higher than 6MP. It was amazing the amount of highlight you could recover in Adobe Camera Raw and the TIFs/JPGs were beautiful, as it’s usually the case with Fuji.
Alas, it didn’t work out in the market, people weren’t willing to trade half their resolution for more DR, turns out. Also, regular sensors got much wider latitude.