How should I query all data platform instances through graphql? The following query doesn't return anything.

query searchDataPlatformInstance {
  searchAcrossEntities(
    input: {types: [DATA_PLATFORM_INSTANCE], query: "", start: 0, count: 1000}
  ) {
    start
    count
    total
    searchResults {
      entity {
        urn
        type
      }
    }
  }
}

Searching for Data Platform Instance directly is not yet supported cc @bulky-soccer-26729 who has been thinking of this

Thank you John! Is there any alternatives to retrieve all the platform instances that belong to one or more platform?