Current one part of the partition can be stay AVAILABLE and therefor it is not possible to read key's in a DEGRADED partition as it might be stale.
But for some reason it might be worth to be able to read such keys.
In that case it must be ensured that no partition enter AVAILABLE mode and rebalance.
An additional configuration migt force DEGRADED mode for all partitions, in this case it will be possible to have read access to all keys where this part. does not have all owners AND have full access if all owners are available.