ChatGPT Performance Optimizer от Huckleboard

Built with their own product to fix the performance problems OpenAI won't fix

Long ChatGPT conversations slow down your browser as hundreds of message turns pile up in the DOM. This extension automatically unloads older turns while keeping the last 40 (configurable) visible, which massively reduces lag and memory usage.
Its streaming-aware, so it never interferes with active responses. Includes a live status chip and one-click disable. Zero data collection. Everything runs locally on chatgpt.com.