That 8 minute default feels more unsupported than outright broken, same controls with only staleness different and it still passed their own check. Whether surge windows need more slack is really a question for the volatility data. Capture skew still works when captures aren't simultaneous, but it misses staleness at the source, so caches need their own detection. The generated timestamp helps when exposed but caches can overwrite it and it's unclear if it means issued or rendered, so pair it with cart vs checkout divergence and observed volatility, and just persist eligibility and cache age at capture time since neither rebuilds after the fact.

Also the session_state_unknown check is treated as fatal but the article never shows how that flag actually gets set, if it comes from real line items it's fine, if it's weaker a flipped session could slip through so that reads more like a gap to clarify than a confirmed bug