relax p2p propagation time, it was too close to L1 block time

op-node/p2p/gossip.go

@@ -226,8 +226,8 @@ func BuildBlocksValidator(log log.Logger, cfg *rollup.Config) pubsub.ValidatorEx
 		// rounding down to seconds is fine here.
 		now := uint64(time.Now().Unix())
 
-		// [REJECT] if the `payload.timestamp` is older than 20 seconds in the past
-		if uint64(payload.Timestamp) < now-20 {
+		// [REJECT] if the `payload.timestamp` is older than 60 seconds in the past
+		if uint64(payload.Timestamp) < now-60 {
 			log.Warn("payload is too old", "timestamp", uint64(payload.Timestamp))
 			return pubsub.ValidationReject
 		}

specs/rollup-node-p2p.md

@@ -276,7 +276,7 @@ An [extended-validator] checks the incoming messages as follows, in order of ope
 
 - `[REJECT]` if the compression is not valid
 - `[REJECT]` if the block encoding is not valid
-- `[REJECT]` if the `payload.timestamp` is older than 20 seconds in the past
+- `[REJECT]` if the `payload.timestamp` is older than 60 seconds in the past
   (graceful boundary for worst-case propagation and clock skew)
 - `[REJECT]` if the `payload.timestamp` is more than 5 seconds into the future
 - `[REJECT]` if the `block_hash` in the `payload` is not valid