check below links on throttling

https://stackoverflow.com/questions/49899765/how-to-disable-throttling-in-lighthouse-programmaticaly?rq=1
https://github.com/GoogleChrome/lighthouse/issues/4376
https://github.com/GoogleChrome/lighthouse/blob/master/docs/configuration.md
https://github.com/GoogleChrome/lighthouse/blob/master/docs/throttling.md
https://github.com/GoogleChrome/lighthouse/tree/master/docs/recipes/custom-audit

Run test using

node_modules/.bin/mocha spree.spec.js

get spree app

https://github.com/spree/spree