Thank Charles for your message !
A couple of thoughts. The first sunset image has a clip from the sensor possibly ?
I have looked quite a lot at this image and there are not a lot of picture formations that handle it well. Here is an example with OpenDRT :
About the second issue, I think I reported something similar in this thread with the blue gradient example.
This answer was given to me back then :
But I would just expand on it to say that we sacrifice having a nice image appearance for every possible source image “out of the box”, in order to hit the corners and be invertible. You can of course use an LMT which “rounds off the corners”, and will therefore smooth out the appearance for extreme images such as the pure blue example.
Regards,
Chris