Passing CRM ID via Web Messaging SDK startChat() without losing state

We are attempting to inject a CRM customer ID into the Genesys Cloud Web Messaging SDK during initialization. The requirement is to have this identifier available in the subsequent conversation metadata for our downstream Terraform-driven analytics pipelines.

The current implementation looks like this:

const client = new GenesysCloudWebMessaging.Client({
 organizationId: 'our-org-id',
 deploymentId: 'deployment-uuid'
});

client.startChat({
 conversationData: {
 customer: {
 identifiers: [
 { name: 'crmId', value: 'CUST-998877' }
 ]
 }
 }
});

The chat initiates successfully, and the UI renders. However, when we query the conversation details via the API immediately after, the conversationData object is empty. The customer identifiers are not persisting. We have verified that the deploymentId is correct and the SDK version is the latest release. Is there a specific configuration required on the deployment side to allow custom attributes through startChat, or is this data structure incorrect? We need this data to flow through cleanly without additional API calls post-init.