docs(streaming): add 'Things to consider' on high-frequency WS usage and throttling

Notes on heap fragmentation, UDP saturation, throttling/coalescing, buffer reuse, yielding, and payload sizing for reliable streaming/broadcast.

docs/StreamingAPI.md

@@ -78,3 +78,21 @@ Notes:
 Related docs:
 - [`ClusterBroadcast.md`](./ClusterBroadcast.md) — centralized UDP broadcasting and CLUSTER_EVENT format
 
+### Things to consider
+
+- High-frequency updates can overwhelm ESP8266:
+  - Frequent JSON parse/serialize and `String` allocations fragment heap and may cause resets (e.g., Exception(3)).
+  - UDP broadcast on every message amplifies load; WiFi/UDP buffers can back up.
+  - Prefer ≥50–100 ms intervals; microbursts at 10 ms are risky.
+- Throttle and coalesce:
+  - Add a minimum interval in the core `cluster/broadcast` handler.
+  - Optionally drop redundant updates (e.g., same color as previous).
+- Reduce allocations:
+  - Reuse `StaticJsonDocument`/preallocated buffers in hot paths.
+  - Avoid re-serializing when possible; pass-through payload strings.
+  - Reserve `String` capacity when reuse is needed.
+- Yielding:
+  - Call `yield()` in long-running or bursty paths to avoid WDT.
+- Packet size:
+  - Keep payloads small to fit `ClusterProtocol::UDP_BUF_SIZE` and reduce airtime.
+