I've never really understood why it's a desirable feature to have automatic HDR-to-SDR in the first place. No one is making HDR-only content and the official SDR master for every movie and TV show done by a human is always going to beat a fancy LUT.
When performing colour grading you're always deciding what parts of the image need what amount of contrast etc. based on what's important to see in the context of the scene. When grading to HDR you're going to make different choices simply due to the fact that you have a wider dynamic range available. Even putting aside the fact that you're not starting from the same raw inputs that the production studio is working with, automatic tone-mapping is never going to be able to look at a scene in the same way that a human does and decide which parts are important and which parts aren't.