In the NEXT update, GIF will also support the "Frame Interpolation Only" mode, just like video. Additionally, there will be some UI updates related to GIF Frame Interpolation.
I'm also working on preserving the alpha channel (transparent background) after GIF frame interpolation, and implementing "Target FPS" mode for GIFs, which could be available in the next update or near future updates.
Original

2x Frame Interpolation only

Original

2x Frame Interpolation only
