Documents the stirring-induced rate noise problem, its root cause (post-differentiation filtering), and three mitigation options: pre-filter before differentiating, sliding-window regression, and model-based rate from Pot.p_pot (Smith only). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NSo8R6GjoBQdStB3j67zSs