bradytheinventor
commented
2 years ago Save/load settings could be useful, especially as the tool gets more features. It might take a lot of rewriting to implement though.
Have you tried the context-sensitive multi-drag-drop? You can select all your input files and drop them into the tool to create lots of entries quickly. It is smart enough to only put pictures in picture slots, music in track slots, etc. You can even drop in a text file to set the track names all at once.
Having to add the songs and associated music disc textures by hand every time you want to add a song to the datapack/resource pack is very tedious and time consuming if you have many songs.
A way to load a previous setlist to work on again would save a lot of headache.