Usually a few days after my initial processing of an imaging run, I go back and look at the data and try to decide if my initial processing extracted everything that was possible. The answer is nearly always no. In this case, I'd processed the Lion Nebula the morning after I imaged it on 9-21-22. It told me that basically I should go back and image the nebula for another 8 hrs and add that data to the stack and reprocess.
Weather didn't cooperate last night so I went back and looked at the data and decided I'd reprocess.... that a lot had been left behind in my first processing. I like this result a lot better, especially for only 4 hrs of imaging in Bortle 5-6 skies.