The idea of having sliders to choose images within a slot in Spine is a great suggestion and could indeed streamline the workflow for animators. Currently, Spine does not have a slider feature for selecting images within a slot, but there are discussions and suggestions about improving the UI for easier navigation and selection of images. For now, you can use the tree view to switch between images in a slot, and there are plans to potentially add a chooser UI that could help with this process. This feature would need to load images dynamically, which could take some time if the images are large, but placeholders could be used until the images are fully loaded.