Firezone has released sanstun, a Rust WireGuard library replacing its BoringTun fork. It separates network I/O, time and randomness from protocol state and lets worker threads perform cryptographic operations. For 1,280-byte packets, bookkeeping accounts for about 2% of encryption time; the claimed potential speedup above 45 times is theoretical and excludes thread-handoff overhead, not a measured end-to-end throughput gain. The repository states that no formal security audit has been completed. Callers remain responsible for IP validation, adequately random seeds and other integration safeguards.