One long run folds its history instead of failing
A single long agent run that fills the context can now be folded mid-run, and your newest never and must rules are the ones kept.
When one request kept an agent busy for a long time, its history could outgrow the model's context with nowhere to fold it, because folding only happened between your messages. It can now fold inside a single run, keeping every tool call with its result.
The short list of your rules that survives every fold (never this, always that) now keeps the newest ones when it is full, instead of refusing to add more.
A fold that was thrown away because you switched sessions now waits before trying again, so it never repeats right away.