Working on a new release with some new features, but now just ran into a pretty severe limitation of the DNG profile format, or actually the DNG pipeline which applies it.
The DCP LUT is HSV-based. Hue is changed by adding an offset. To interpolate between table entries you calculate an average of the neighbors.
Say if entry A says hue -30 degrees, and entry B says +40 degrees and we want to interpolate exactly inbetween, then we get (-30 +40) / 2 = 5 degrees, just as we would expect. But say entry A is -170 degrees and entry B is +160 degrees, then we get (-170 + 160) / 2 = 5 degrees, which indeed numerically the average but as hue goes around 360 degrees the average should be (360-170 + 160) / 2 = 175 degrees in his case.
These cases could easily be handled when the LUT is applied, the problem is that the DNG reference code doesn't do that, and I assume Adobe Lightroom doesn't either (haven't tested Lightroom yet). This means in practice that hue rotation is limited to the range -90 to +90, which indeed should be enough for making colorimetric corrections, but is an issue when designing looks, even with very mild looks there is a significant risk to run into this discontinuity. The reason for this is that for lower saturation colors hue rotation can be quite huge in the RGB-HSV space despite that there is a small adjustment in visible space.
It's actually not a limitation of the LUT format itself, but how the LUT is applied. Forgetting about hue angle discontinuity is a classic bug when working with a coordinate system like HSV, JCh or other that has hue defined as an angle; been there, done that. It's a bit unfortunate that Adobe has limited their DNG profile format by having this bug in the DNG pipeline, and I'm quite sure that they'd call it a "feature" themselves as you can optimize LUT application if you don't need to care about discontinuity.
I have not yet figured out how to deal with this. If you don't use the look operators it's quite unlikely that you run into it though.
EDIT: you're not limited to +/-90 degrees (although that will guarantee that you are safe), what you need to avoid is discontinuity, that is a jump from say +179 to -179 between table entry neighbors.
