One fun feature that meshoptimizer got in the last two years that I forgot to mention in my v1 post is support for provoking vertex optimization for primitive ID rendering.

It’s a little niche but if you use visibility buffers and can’t use mesh shaders you kinda need it. The implementation is based on exploration by John Hable (thanks!) and is used by Wicked Engine.

https://meshoptimizer.org/#visibility-buffers