You can set different RF values and server counts for the read replica cluster to achieve high availability and low latency reads for users in specific regions. Read replicas are observer nodes that replicate data from the primary cluster asynchronously, but do not guarantee strong consistency or ACID compliance. The replication factor and server count of read replicas are separate from those of the primary cluster, allowing you to customize them according to your needs. For high availability, it's recommended to have a higher node count and replication factor greater than 1 for read replicas.