There is no maximum assertion age and nothing pauses: checkpoints fall back to the last confirmed assertion, so the L1 route still works when the rollup stalls.
Each phase is padded for the full 7-day censorship budget: a 17d voting delay (3d + 14d worst-case confirmation), a 21d voting period (14d + 7d) and a 25d L1 timelock (14d + 8d + 3d), which keeps the same exit window as the L2 path. EOA claims are EIP-712 signatures bound to a single assertion hash on the L2StateMirror domain. Contract delegates register through the L2 DelegateMapping (force inclusion takes at most 24h).
The new L1 timelock holds the EXECUTOR_ROLE on both L1 and L2 upgrade executors, which is the same as the existing L1 timelock.