The scope of the fsm workload development only covered the interaction between the new POS coordinator changes and CRUD operations, it didn't include testing with the balancer, using causal consistency for CRUD operations nor adding/removing shards. Initially there shouldn't be any problem because on one side, the migration take the Distributed Lock which ensures serialization with any other DDL operation, the split is a local operation on the config server that shouldn't affect and the causal consistency code is only related to CRUD, however, this wasn't tested as part of the development. We should take the time to properly test this and ensure there is no problem between the balancer and the DDL and remove the related tags.