Thank you for the feedback. Please let us know if this article helps your scenario: https://docs.microsoft.com/en-us/azure/search/search-howto-indexing-azure-blob-storage#using-blob-metadata-to-control-how-blobs-are-indexed
You can specify if a blob should be skipped during indexing by modifying that blob’s metadata.
Azure Search Product TeamErez Wolf commented
This could work. what if one wants to re-add it to be indexed (ie undo the exclusion)?