Unfortunately problematic pictures contain people, e.g. from weddings, so I’m not allowed to post them, but sure, from now on I’ll be more aware and perhaps catch a photo with “safe” content and problem illustrated.
However, it’s not urgent - I really find darktable extremely useful, fast and convenient. Moreover, its output in terms of image quality, tonality, crispness and colour are basically outstanding.
I’m quite geeky and regularly dig in various other software, including DXO, CaptureOne and SilkyPix, but really, I regard darktable as overall killer winner. 
And there is one more thing - recently one user gave us whole lot of grief and aggression. Contrary to him I see one extra thing rarely mentioned: we not only benefit from using free software, but are also given careful explanation and vast shared knowledge.
Working in printing house I know how complicated and expensive is Colour Management, software and training - Aurélien alone gives us sophisticated knowledge, not to mention all the dedicated users here!
So, I’m following many posts here, meanwhile experimenting, in time I think I will use your expertise 