Ah I see. Yes that makes sense. This tool was made to cover things that Aseprite doesn't cover out of the box. I'm going to work on an update for this if you give me some time.
Can you answer a couple of questions:
1. Why does the Aseprite PNG export not work for your specific case?
2. What file structure format are you looking to achieve? What would be some examples of the end result file names and their content? Attack_001.png, Attack_002.png? Like that?