Dump your raw FHR payload to the console

gistfile1.txt

/* Usage:
  1. open about:healthreport
  2. open a Web Console panel in that page
  3. Pop the console out and expand it
  4. Copy this JS code to the clipboard
  5. Paste it into the command prompt at the bottom of the console
*/

let reporter = Components.classes["@mozilla.org/datareporting/service;1"].getService(Components.interfaces.nsISupports).wrappedJSObject.healthReporter;

reporter.collectAndObtainJSONPayload(true).then(
  function onJSON(data) {
    console.log(JSON.stringify(data, null, 2));
  }
);