Hi, I'm the original author of LibreSpeed. When you load the website it downloads a list of servers and tries all of them to see which one has the lowest ping, that's what you're seeing.
Thanks for clarifying! Took a deeper look on my computer and I guess I learned that NoScript was misidentifying due to the cors or something. Just had to call it out before, as one can never be too careful these days :D
I use iperf3 with Speedtest's servers, personally. But for a browser, yes JavaScript is needed.... But needing JavaScript files from like 20 different domains is typically a red flag for me on any site.
It doesn't need javascript from "20 different domains", only a file called empty.php is fetched from those servers to measure the ping. The javascript is hosted on librespeed.org, which is under my control.