The hassy file has to go through .dng conversion to be operable in ACR, this loses a lot of the hassy data like color accuracy etc. (or so hassy claims... and is correct in my experience with different hassy systems over the last couple of years.)
Whose DNG converter is that? Is it their own production? Where is that to get from?
I can do nothing with the .FFF file. I don't know the format (it is in a TIFF container, but that's not enough). Adobe's DNG converter can't process it (of course; if it could, then ACR would accept it as well).
Anyway, it sounds to be unbelievable, that the DNG conversion loses image data. Color accuracy is no separate information in the raw image, it can not be "lost". There may be another problem: the in-factory calibration of ACR is less than optimal for several cameras. It can be calibrated to yield matching color, or anything you want to. Those, who are very picky about colors, calibrate their camera themselves, because there can be small variations between copies of the same model.
Another problem may be, that their DNG converter generates incorrect color conversion values (in the DNG file).
I guess Panopeeper should get his +4 stop shots soon and we can all get the numbers out all solid and shiny!
I took another look at your previously posted raw images and found green pixels with the value 65536 (on the specular top edge of the Toblerone). Not many, only 3400 of them; that is is 0.0022%, too few to be shown by the histogram.
Still, this proves, that the sensor in fact delivers 65536 levels in ISO 400. Consequently the top level in the newer image, 001136, namely 15000 is still two stops from clipping:Histogram of 001136
As the counters show, there are only about 2200 pixel over 15000, that's negligable.
Now, what does this mean in the praxis?
1. 18.7% of all pixels in 001136 are in the range 0-127. If we start at the right end (i.e. with the range of levels from 32768 to 65535) as +0EV, then the range 0-127 corresponds to -9 EV
2. This shot is not so bad, but Edmund's CF000965 had 10.5% of all pixels with value zero (his other posted shot had 64%).
Now, Edmund may say that this is not a problem for him, he does not want to see details in the deep shadows, only graceful noise. However, this is not so simple. The proportion of the values of the three "kind" of pixels makes the color (with de-mosaicing, of course); this is obvious. What is perhaps not so obvious is, that when one or two colors are on level zero, then the proportion is gone to the dog: on one place it may be (0, 50, 80), on an even darker spot with half the lightness (0, 25, 40). In other words, different shades of the same color can result in vastly different colors. This can appear as color noise, which may be acceptable, typically on very fine structured surface like fabric/cloth, but it may manifest as off-color spots as well.