I've actually got my own (partly - the core halfedge stuff is from another C# project).
But it's performance I'm after. I have three options:
1. Burst compilation
2. Offload to the GPU (not sure if this is even a good use case for GPU compute)
3. Find a native library.
(3) is potentially a quick fix but might limit my ability to add functionality. But it also offers the tempting possibility of getting a ton of functionality for "free".
