when changing animation speed you have to do it in milliseconds. While it’s not too hard math to figure out i always get stumped when i want to set the speed to something basic like 24 frames per second, or 30 frames per second. It would be very convenient if that was just an option by default
Unfortunately Aseprite only actually supports millisecond values rather than FPS values due to how GIFs work. Adding support for framerates that don’t cleanly fit in 1 millisecond intervals would require a lot of work.