ElasticSearch - Highlighting

We are trying to provide an experience to highlight all occurrences of a term in a given document. Going thru the doc about 'Highlighting' in ES, i would like to understand if there are any customization with good performance around 'postings' to achieve the same. Plain or FVH seem to be quite less performant and space consuming respectively.

'Postings' highlighter suits our needs but we need to restrict the highlighting only to the term and not the entire sentence.

_Note: Highlighting a given term if it is a substring of any string is out of scope and not keen on implementing it at this stage.

Please let me know if there are ways to achieve term highlighting efficiently.

-Divya Malini