Thanks, that was a useful suggestion. Just discovered WebPconv which is super useful. Incredible compression.
However while it helped a little, it still didn't fix the issue. I feel like the preload animation action is not working as it makes little sense why it stutters so bad.
While the animation takes up the width of the screen and is 33 frames, with the WebP format it is only 620k (as apposed to 40mb before).
I cannot understand why it would stutter with such a small amount of data. Especially if it was preloading it.