Only half-joking. Your website spins at 100% cpu on my machine (firefox). Unfortunately it's one big fistulated mass of minified javascript so, not really debuggable.
sigh i miss the days when the web wasn't an app-delivery mechanism.
Running the latest, unmodified release from https://github.com/LemmyNet/lemmy
As you've already hinted at, that JS is most likely related to the PWA part of lemmy.