const EPOCH_CHANGE_LOOKAHEAD: u64 = 3;Expand description
Epoch changes claiming an epoch further ahead than this are dropped at
intake. We could not verify them anyway: an epoch’s stake table only
materializes by walking the DRB chain, so parking such a message and
driving catchup for an arbitrary claimed epoch just burns resources.
Within the ceiling, deferred changes verify progressively as catchup
advances (CertVerifiers::retry_pending runs on every DRB arrival).