The Lens module was created to digitally correct for lens distortions and some types of chromatic aberration in the more affordable lens systems, mirror systems and eyepieces.
One of the many uses of this module is to digitally emulate some aspects of a field flattener for those who are imaging without a physical field flattener.
While imaging with a hardware solution to this type of aberration is always preferable, the Lens module can achieve some very good results in cases where the distortion can be well modeled.
Just like in real life, in astrophotographical image processing, some things need to be done in a particular order to get the correct result.
'Brightness/Color detail loss' specifies a measure of allowed acceptable detail loss in order to reduce noise.
You can convert everything you see to a format you find convenient. Give it a try!