I'm playing with your dither mod and the base game, no DLC.

The following entities still have animations:
- player character (even when not moving)
- belts
- belt reader
- trains
- train stop
- inserters
- spidertron (even when not moving)
- burning trees
- biters
- explosion from entity destroyed
- bobbing of flying robots
- worms go up and down
- rocket silo (turbine on the left side)
- splitter
- smokes: steam turbine, stone furnace, burner miner, burning trees, trains

Some of these might be intentional, but it would be nice if they were documented.

Also the electric miner graphics look broken in some orientations: it looks like one side is not (properly) connected to the rest. They also look very weird without the actual drilling part.

Thanks for feedback, however the mod was primarily made for improving load times and VRAM usage for mod developers, while keeping the game recogonizable. Player animations, belts and splitters are intentionally left out to not be too distracting. Some of the things you listed, like bots, inserters, spidertron and trees, are not regular animations, and removing them won't cause performance improvements. There was never a plan to completely remove all animations, and i don't see a good reason to.
Some animations like biters, trains and cars are much harder to remove in a way that keeps the ability to face any direction. Some like explosions, smoke and corpses will be removed in a later update. I have missed the rocket silo and train stop though, and will also look closer at what worms do as they're a bit weird, so thanks for pointing those out.

If you do want some things to be different i can add some settings though, like for character and belts/splitters

I think a settings for belts and splitters will be nice (I think static splitters might not be that noticeable, as they only move when items pass through, so maybe have the settings separate).

About the character, it kind of depends on how it will look I think. Is it possible to affect only the stationary animation? The same for the spidertron.

To be honset i don't really think touching neither character nor belt entites would improve anything, but they do have a lot of sprites and it may be faster to load the game if it doesn't need to pack all of them into atlases. Will measure the impact and add the settings if needed in a future update.