I had a few minutes free and it seemed easy enough to add support for GIFs stored in a C header file so I did it. It’s pushed to GitHub but not released, so you’ll need to download the library from GitHub, not from Arduino Library Manager. Check the AnimatedGIF library for instructions on producing the header file from a GIF, I haven’t done it myself, I just used one of their test images. LMK how it goes, I didn’t test the code thoroughly.