[dreamcompiler]

You're describing perceptual clipping, which is orthogonal to dynamic range (DR) compression. There's no reason you can't do both, but HDR photography has traditionally been about capturing a wider range than the camera's sensor can handle and then mapping that data into a narrower range. That "narrower range" is determined by what the display technology is capable of and what common file formats assume. Nonlinear perceptual response curves and clipping can of course be factored into the mapping, but that mapping process is still DR compression.

None of the above has anything to do with data compression which JPEG does to decrease the number of bits needed to store a file; that's a different concept from DR compression.