The multi-request, blocking page load has me a bit worried. A course page like this takes 10 seconds to load over a simulated 2G connection and up to 20 seconds to hard reload, meanwhile refreshing itself and dramatically changing layout several times. An enwiki page load, for comparison, takes 1 second and 4 seconds, respectively.
If you want to experience this, you can throttle your browser's network connection in Chrome and Chromium using the Developer -> Network Conditions tool.
One solution to consider is doing all initial rendering inline. Substituting refreshed content after page load can behave the same as it does now (does it?).