Hi Nik,
Thanks for the explanation of the “Use Levels” option, I hadn’t realised it was a Curves/Levels toggle.
What I’d like to avoid any direct automatic adjustment of colour intensity (vibrancy/saturation) if possible. Something closer to the Auto Option of the Light controls in Apple Photos which only adjusts what would basically be the Tone functions in Nitro.
This may just be an edge case with the particular way I like to work, but I felt it worth mentioning as it’s an ability I have with other tools.