Booting a multi-instance Tarantool replicaset under replication.failover=election: box.cfg() BLOCKS until a quorum (N/2+1) of peers is reachable, so anything that runs after box.cfg — a custom role's apply(), its listen port opening — won't happen on a single instance until its peers also start. A boot script must launch ALL instances first, THEN wait for each one's readiness; waiting for instance-1's port before starting instance-2 deadlocks. Pattern in examples/tarantool-ee-self-hosted-etcd/Justfile (up-file). Also seen: a transient 'Quorum collection for a synchronous transaction is timed out' during role apply on a racing fresh boot — recovers on retry.