In Rust, BaseNetworkable.clientEntities contains thousands of world objects (trees, ores, barrels, animals, players).

If you iterate all 15,000 entities every frame, your external overlay will drop to 20 FPS.

Multi-Threaded Entity Caching Solution:

1. Spawn a dedicated background worker thread that iterates clientEntities once every 200ms.
2. Filter and store active players (BasePlayer) and relevant loot in an atomic thread-safe double buffer.
3. The main render thread only reads the small cached array of ~30 nearby players at 144Hz.

Zero frame hitching, render overlay runs at solid 240 FPS!

Double buffering entity lists with std::atomic<bool> flip flag is the best architectural pattern for external game overlays.

Implemented this and CPU usage dropped from 28% down to 1.2%.