I have CosmosDB Vector Vcore - M30 (Cluster tier), Need to Enable Full text search BM25

Request: Enable Azure DocumentDB full-text search with BM25 ranking (gated preview) on our cluster. Current behavior: $search only supports cosmosSearch / knnBeta; $search: { text: ... } fails with “Unrecognized $search option: text…”. Goal: Use BM25 lexical ranking + hybrid search (vector + lexical) in aggregation pipelines. Cluster: <cluster/account name>, RG: <resource group>, Subscription: <sub id>, Region: <region>, MongoDB version: 8.0. Use case: We store document chunks (field text) and embeddings (embedding 1536 dims) and need high-quality lexical relevance + hybrid retrieval for Q&A / summarization. Docs reference: DocumentDB full-text / hybrid search limitation notes BM25 ranking is gated preview.