Interesting... thank you for sharing!
It seems caching doesn't do much, even while also being a big pain for instance admins - so much so that it is explicitly made voluntary.
Perhaps that is why PieFed is going so hard on integration with PixelFed and now Loops.
Tangentially, there's a whole bunch of issues going on with the programming.dev server for one. See at !meta@programming.dev. Lemmy's upcoming upgrade to 0.19.6 should help - see https://github.com/LemmyNet/lemmy/pull/4623 and https://feddit.org/post/3524876 discussing it.