Gifcurry does not optimize using Gifsicle. It employs the optimizations afforded by ImageMagick. In most cases the Gifsicle file size reduction is only minimal (even with the "-O3" flag).
Still, if desired, I could add this extra step.
Thank you for commenting.
- lossygif for small size, based on gifsicle, https://kornel.ski/lossygif
- Gifski for high quality, based on pngquant, (https://gif.ski/)
Both are made by Kornel Lesiński. Lossygif is actually result of a pull request being ignored by gifsicle maintainer(s) for years – more details in a recent HN thread: https://news.ycombinator.com/item?id=16573627.