How to speed up fetching MediaItem with gatsby-source-wordpress?

I'm building with Gatsby + WordPress, and the WP media library has 1000+ items; this takes a very long time to download during every fresh build:

How can I have gatsby-source-wordpress fetch multiple images simultaneously? It appears that it fetches them sequentially.

My current gatsby-config.js options for gatsby-source-wordpress:

resolve: `gatsby-source-wordpress`,
options: {
  // the only required plugin option for WordPress is the GraphQL url.
  url: process.env.WPGRAPHQL_URL,
  schema: {
    timeout: 30000,
    perPage: 500,
    requestConcurrency: 50,
  },
  type: {
    MediaItem: {
      localFile: {
        requestConcurrency: 200,
      },
    },
  },
},

Wondering if this is a frontend tweak needed, or something to adjust server-side.

The requestConcurrency: 200 setting in localFile doesn't appear to affect anything here.