Actually, I use Rawtherappee for adjust the Black and the white points cause I can see in real time areas that are too dark or too white. I tried to write a script-fu to make the same with Gimp 2.10 bur it doesn't work properly... and it's too long to apply

If Gimp conceptors could add a similar tool, I think many users should use it

Thank you very much

As usual, wishes are already granted to those who read the doc (or explore the UI a bit)... See "View>Display filters" and the "Clip warning" filter: