I see that you included Reworder functions, but don't forget Violet's another find, being adding animations to animations. Also, you didn't mention any new better way of adding frames to animations; I'd myself recommend some drag & drop system, a possibility to multiply a given frame (like, right click > multiply > writing "30" in a text box > 30 frames of the same tile appear) and working ctrl+x, ctrl+c, ctrl+v. Or something.