How do stateless_http and json_response flags relate to each other?

These flags control different aspects and can be set independently. stateless_http removes all session state, disabling the primary SSE connection and all server-to-client communication, which is the more drastic option needed for horizontal scaling. json_response only changes how POST responses are delivered, replacing SSE streams with plain JSON, but can still work with sessions and the primary SSE connection. You can enable json_response alone for simpler responses while keeping full bidirectional capability, or enable both for maximum simplicity at the cost of maximum feature loss.