Hi Mike,
We just had an HDR event at Editors' Lounge. What I can tell you now is that there isn't a "workflow" for HDR yet. We are in the alpha stages with this stuff. There are multiple "standards."
The only shipping reference monitor is Sony's BVM OLED and it only hits 1K nits when Dolby wants 4K nits. While Dolby has a 4K nits monitor, they aren't selling it. Unless you are the size of a Warner Brothers or Technicolor, you can't get your hands on one of them. Otherwise, you are going to be using a Vizio consumer TV to color correct.
Filmlight worked directly with Dolby to create their DolbyVision workflow, so that is your current best option if you need to get one done and can get the Dolby monitor.
Dolby has their own box to do an "automatic" conversion from your HDR color pass to an SDR (Standard Dynamic Range, or what we have now) that has minimal adjustability for fixing things. I personally think we will be doing two color passes as you are going to develop a different aesthetic for HDR correction. Why?...
Adding the much brighter white point really adds to the impact of the picture. Right now, if there is a glint off a car window on a bright day with a blown out sky, you would probably put the sky at 100 IRE and that is also where the now clipped glint would live. In HDR, a white sky at maximum IRE (4K nits or 40 times brighter than current TVs) would give you a sunburn and force you to wear sunglasses to watch TV. So maybe the sky (which will probably not be blown out in HDR) might be at 80% and the glint on the car goes to 100%. So where do you put the face in that? And how does a box automatically adjust for that creative choice? Problematic at best.
So as I said in the beginning of this post, we are in the wild wild west of developing HDR workflows, standards, and aesthetics. That said, this is the first real improvement to our final product that I have not only been excited about, but truly see the value in during my professional career.