In order to take advantage of proxySQL multi schema design, it would make more sense to control the priority of failover using mysql_servers table using a "failover" hostgorup for read and write, which will be used only to dictate the order in which failover must occur. In this case, one can change the server order as it will on mysql_server table, once all changes are done, issue a LOAD MYSQL SERVERS TO RUNTIME and the script should query runtime_mysql_servers.

This also allows for proper weight of readers.