July 2026: Performance-focused delivery for block/buzz with four major improvements. 1) Markdown Rendering Cache Optimization reduced re-parsing during channel switches and reused element trees across remounts, with E2E tests validating cache hits and zero fresh parses. 2) Desktop App Rendering Stabilization fixed unnecessary app-shell re-renders on keystrokes, resolved latent cache races in editing and profile updates, and moved activity timestamps to refs to improve presence accuracy. 3) Thread Panel Rendering Optimization replaced identity-based memoization with value-based equality, boosting rendering efficiency; introduced a typing-latency benchmark to quantify responsiveness under heavy agent activity. 4) Agent Identity Restoration Synchronization and Mention System Update synchronized startup/shutdown to prevent race conditions, ensured restoration after workspace identity initialization, and updated persona ID resolution for active agents. Business value: snappier UI, lower CPU usage, more reliable identity/presence flows, and expanded test coverage.