At present, Shotcut doesn’t generate optimised palettes for animated GIFs. This can be worked around by exporting the output as a video file, then running it separately through FFMPEG, as a lovely user pointed out here:
For high-quality GIF conversion, consider exporting the Shotcut video as Ut Video Lossless, then use FFmpeg to generate an optimized palette. The command looks like this:
ffmpeg -i Input.mp4 -filter_complex “[0:v] split [a][b];[a] palettegen [p];[b][p] paletteuse” Output.gif
If this could be incorporated into Shotcut for all animated GIFs, it would make the program a one-stop-shop for creating high-quality animated GIFs, avoiding the need for other programs.