Dedicated byte ArrayPool isolated from System.Buffers.ArrayPool.Shared. Rationale: ArrayPool.Shared is process-wide and contended by every library running in the host (the BCL itself, ASP.NET if hosted side-by-side, JSON serialisers, gzip streams, …). Under high concurrency, even though Shared has thread-local caches, the cross-bucket fall-through paths take locks that show up in profiles. By renting Suave's per-connection buffers (line buffer, header read buffer, header-name lowercase scratch) from a pool we own, we keep our hot-path rentals out of that shared contention surface entirely. Tuning: ArrayPool.Create defaults are 1MB max length, 50 arrays per bucket. Suave's typical rentals are 8KiB and 256B; the defaults are appropriate.

Cached HTTP date string to avoid formatting on every request. HTTP dates only change once per second, so caching provides significant benefit.

Dictionary pool for HttpContext userState

StringBuilder pool for dynamic content generation