This part is beautiful:

> Serialization Protocol: The library uses a custom "Envelope" protocol (PayloadType.RAW vs PayloadType.LIB). This allows complex objects like Mutex handles to be serialized, sent to a worker, and rehydrated into a functional object connected to the same SharedArrayBuffer on the other side.

It's kinda "well, yes, you can't share objects, but you can share memory. So make objects that are just thin wrappers around shared memory"