Handling of HDR iPhone photos

Photos shot with iPhone display in Apple Photos with HDR highlights that are not visible in Nitro. Presumably Nitro does not support the image format that these highlights are recorded in.

My question is, what changes (if any) can one make to an image in Nitro without damaging or discarding those HDR highlights? Is it safe to make metadata changes such as assigning star ratings? Is it safe to crop? I assume that modifying any sliders will “lose” the HDR elements of the image (though of course these could be “recovered” by resetting the adjustments made to the image).

If it were possible in a future release to display and enable editing of the HDR highlights along with the “base” image data in Nitro, that would be amazing.

For the record, Photomator supports this somewhat when you enable its “HDR editing” setting, which not only displays HDR highlights for iPhone photos, but also displays similar “HDR highlights” for RAW photos shot on other digital cameras (using highlights recovered from the RAW image data). The effect is very pleasing when viewing unedited originals. Unfortunately, when you edit photos in this mode, Photomator seems to redistribute the image data between the “base” and “highlights” layers of the resulting image in such a way that devices that cannot display the HDR highlights are left with a washed-out image, unacceptably lacking in highlight detail. When I traded messages with Photomator Support on their user forum about this, they ended up replying that their “HDR editing” feature was a little under-baked, and that they advised against using it unless I was happy with only viewing the resulting images in Photomator. About a week later, Photomator was acquired by Apple, and the user forum was deleted from the Internet.

Anyway, if it’s possible to do this well, I think there’s an opportunity for Nitro to “outshine” Photomator in its HDR support, although I assume if it was easy to do well, Photomator would have done it.