Update_by_query taking a partial document

Elastic Stack Elasticsearch
2

It seems you can do something like:

{
  "query": {
    "bool": {
      "filter": {
        "term": {
          "customer.id": "2"
        }
      }
    }
  },
  "script": {
    "lang": "painless",
    "inline": "ctx._source.customer = params.customer",
    "params": {
      "customer": {
        "id": 2,
        "name": "CustJ4",
        "anotherProperty" : {
          "foo" :123,
          "baz" : true
        }
      }
    }
  }
}

Which overrides the embedded/nested document (although this approach isn't documented so it's not clear if it is an officially supported approach).

It would be nice to be able to do a partial document update in a similar manor (without the complete override). Anyone got anything to say on this?

Thanks, Rob.