Interesting development, but the results (Version 1.0.3) are vastly over denoised and overscharpened. Block artifacts are adequately suppressed.
TIFFs directly out of J2R are unusably oversharpened, so I'm forced to use Capture One Pro to repair the oversharpened images.
When I open the DNG output in Capture One Pro, I need to apply a minus 60 on the Structure control to get something near usable.
Also, the noise reduction kills shadow detail which it mistakes for noise, and that's on the "Normal" setting..
What's probably needed is a newly trained AI model for a 'Low' or 'None' setting of the Noise & Blur reduction control.
Because of the missing shadow detail, it is hard to see if any of the claimed Dynamic Range expansion is produced.
The highlights also do not show clear signs of recovery which, together with the featureless shadows, make the claimed dynamic range expansion questionable.
Here is a source JPEG, a frame taken from the BladeRunner 2049 movie:
On the TIFF output (which I cannot upload here), patches on e.g. the forehead have become completely featureless, and other parts of the image, like e.g. the beard, are way over-sharpened/processed.
And here is the result, JPEG output via a DNG, after a huge (-60) reduction of the Structure control in Capture One Pro to 'repair' the oversharpening. Details in e.g. the dark parts of hair and on the forehead are already completely gone: