Excellent work!
You probably know much than me on this subject but here are some possible causes/solutions for slow loading .gif's from: https://www.cnet.com/how-to/how-to-make-your-gifs-load-fast-every-time/

Delete excess frames

The main reason why your GIFs load so slowly is likely because you have too many frames in the GIF.

Another easy way to reduce a GIF's size is by minimizing the number of colors used in the GIF.

Compress your GIF

Once you have your GIF just the way you want it, it's time to reduce its size some more. Compression diminishes the file size of the GIF without reducing its quality, making it load more quickly.