I never thought about using linear profiles in this manner and would have a hard time making a good case for using linear profiled RAW conversion directly in an HDR merge scenario. I’m somewhat surprised and impressed the the linear HDR merge was better than the Adobe Color HDR merge. The reality is that just switching to a linear profile, as mentioned in the linked article, is actually taking a step backward to a more native representation of the RAW file data. Pushing this unprocessed data directly into HDR Merge is likely the reason for of the more unprocessed looking HDR merge image that resulted. The main reason for switching to a linear profile, in my mind, is for the control and creativity it makes possible in Light Room/Camera Raw. That means using the sliders in the Basic panel or at least clicking the “Auto” button. Whether or not this added level of control would still be available in the HDR-merged image is not something I could speak to as I’ve not tried this. Bottom line is that I wouldn’t advocate using a straight, linear profiled image for anything other than the starting point for making Lr/Cr adjustments. There may be additional uses for the linear profile and this experiment may have turned out better with a linear profile + Auto starting point. However, it is important to keep in mind that applying the linear profile creates, by definition, a less-processed image. That opens up new opportunities, for sure, but exporting the immediate results to another process seems to have missed an important step.