Web Messaging SDK: Custom Guest Attributes Persistence

Quick question about injecting custom attributes into the Web Messaging guest identity. I am using genesyscloud.messenger.messaging.setGuestAttributes({ customAttributes: { userId: '123' } }) before initializing the session, but these attributes vanish after the first message exchange.

Does the SDK require a specific init configuration flag to persist these attributes across the WebSocket connection, or is this a limitation of the guest identity model?