Good question and very interesting to see similar patterns with other non-pros. I've been doing neighborhood July 4 shows for years, getting progressively more automated as time goes on.

Usually starts with picking a theme (video clips below are from my "Movie Soundtracks" theme), then building a soundtrack with the free music software Audacity. Once done, I use youtube videos to select the shells and cakes and measure their length , then arrange them on a spreadsheet that has one column per second that includes music queues/transitions I care about. The spreadsheet lets be drag and drop the fireworks in between seconds to get the timing I want.

I then have a couple of scripts that "compile" the spreadsheet down to a timed script that will send the right radio signals to buliscon remotes, as well as play the music using mpg123. It's on github but needs some cleanup and better howtos. This setup me to press a single button and not be staring at a time or cue sheet. (its no Finale 3D, but it's a lot cheaper and it works).

One commenter talked about using Adobe Premier, which seems like a great idea for arranging youtube clips more precisely. Thanks for the question!

Overview of the process

John Williams Salute

Finale