Idea from @Krinkle at the offsite: Deploy a static version of an article on our domain so we can have it as a benchmark to "know" better if the problem is on Wikipedia or the tool we are using. We tried out having only the header/footer before but that is so fast so it didn't help us, we need to have some actual content on that reference page.
The static page now exists. Once monitored by WebPageTest/WebPageReplay, it will allow us to differentiate betweenp perf impact triggered by wiki-related changes (MediaWiki software, its configuration, and user-generated content) and infrastructure changes (e.g. Varnish/Nginx in prod, or the proxy and browser we use and the test server it runs on).
I've filed T211487 for the similar task for an on-wiki page.
Added it to both WebPageTest and WebPageReplay, they are under static: