Enjoy your final image!
If you find that, despite your best efforts, you cannot get a significantly better result in StarTools than in any (yes any!) other software, please contact us.
The Color module is very powerful - offering capabilities surpassing most other software - yet it is simple to use.
Edges > Threshold; selects all pixels that are likely to belong to the edge of a feature.
AutoDev will keep solving for a global strecth that best shows the detail in your RoI.
You can convert everything you see to a format you find convenient. Give it a try!