If you keep trying to use GUI to do what you want you’re gonna have a bad time. The majority of Linux users doing power stuff like this will use the terminal. Because of that, the GUI is unfortunately underdeveloped.

It’s good once you learn it though. Let’s say that tool never existed. I could easily write a bash script to compress images in cbr or cbz myself. Or autoconvert all cbr files to cbz. Or watch my downloads directory for new files and do that automatically. It’s very flexible and empowering if you learn it. Nobody can make a GUI for every single thing people want a script for.

I learned how to do it purely to get free food at a restaurant. The idiot proof method takes about a day to learn and a bit longer to do reliably. Recommended!