As per our latest research being accessible, responsive, and scalable isn't the only parameters to discover performance of a website and truly isn't enough. Third-party scripts does matter whenever you implement it inside your website.
As per conversation with different web specialists working on quite a high profile websites. They hired for the web development, but particularly to keep the performance in mind. They were guide to follow PWA route and were somehow severely restrict by third-party scripts. For more details on PWA checklist please go to the link. Make sure to get everything with HTTPS otherwise you shall get immediately disqualified from being PWA.
Few important points : Client Deliverable
# Give them as little as possible to integrate with
# Async snippet that does the injection of extra markup, handles the initialization/customization in the initial request, and injects the correct styles.
# Caching is the most effective work around, it gives high performance and lower cost, except the updates, since this is hard to roll out.