The bundle supports batching using ReactRelayNetworkLayer or Apollo GraphQL directly. To use batching, you must use "/batch" as a suffix to your graphql endpoint (see routing config). Then you can switch between implementations in your configuration like so:
For Relay (default value):
overblog_graphql:
batching_method: "relay"
For Apollo:
overblog_graphql:
batching_method: "apollo"
Done!