Router to Subgraph Request using GET instead of POST

How can my Apollo router make GET requests to subgraph instead of POST? Based on my benchmark, GET outperforms POST. But it only happens between the client & the router. I want to improve the network performance by making GET requests from the router to the subgraph instead of POST.

the yaml

federation_version: =2.0.1

    method: GET // does not work
    routing_url: http://localhost:8081
      file: ./subgraphs/product.graphql