I can add another data point to that. Flight with 4J showing, no redemption seat available, used 2 of the upgrades via the call centre. Very helpful person on the end of the line.They are quite flexible in relation to rewards availability, I've been told that if they are at least 2 cash seats available, they are happy to release one as reward when calling for points or complimentary upgrade. And if you call on the day, there's no requirement that there's more than one cash seat available.
