Hi there!
More support is planned actually, the timeline update is now in beta and will be publicly available soon, that further expands the animation possibilities. GIFs and Spritesheets can currently be imported in SpriteMancer.
3D is very primitive at the moment, but more options are planned and they will be coming this year.
Color palettes cannot be customized inside the app (you can enable/disable single colors). That's not planned but It's something that I can look into adding.
You can check the current roadmap here: https://codemanu.notion.site/e9d17c49c5934be1a455627285fcf76d?v=2cca6f98bf9e4d9e...