Most modules come with presets that quickly dial in useful parameter settings.
These presets give you good starting points for specific situations, and for basing your own tweaks on.
Preset buttons can be distinguished by their icons; they bear the icon of the module you launched.
The Filter module allows for the modification of features in the image by their colour by simply clicking on them.
Whatever detail lies outside the RoI, is simply forced to conform to the stretch that was designed for the RoI.
This too is common practice in the realm of documentary photography.
You can convert everything you see to a format you find convenient. Give it a try!