There's a suggestion on polygon sprites trimming (though I'm not sure if it's doable and reasonable).https://www.codeandweb.com/texturepacker/tutorials/cocos2d-x-performance-optimization
Currently TexturePacker has it only for cocos&unity.
I've asked if their team is planning to implement it to lua-based engines.
One thing I know for sure that with or without this fancy feature Gideros is awesome anyway
"What one programmer can do in one month, two programmers can do in two months." - Fred Brooks