Memory growth in ngrok HTTP tunnel connection pool under sustained load

Goal: Determine whether the default idle timeout for ngrok's HTTP connection pool appropriately balances latency and memory usage in long‑running tunnels.

Constraints: The pool’s idle timeout is governed by the undocumented environment variable NGROK_POOL_IDLE_TIMEOUT, which currently defaults to a relatively high value, and enabling the inspect API adds additional request retention that can exacerbate memory growth.

Questions: What idle‑timeout value limits memory growth without noticeably increasing latency? How does the inspect API’s request storage interact with the pool timeout? Should the pool timeout be exposed as a documented configuration option?