Yeah the motion blur you used for the fireworks look is nice. I only posted my example because it reminded me of something I did many years ago with a free open source s/w called Aviutl. I'm not sure it is even worked on anymore. It's why I still have a Win VM on my Linux system.

I have used Natron in the past, but don't like Node based editing, so don't bother with it. Lot's of good open source video editors/compositors to choose from in Linux.