Off-topic: is the rate-limit because they host on a Cloudflare compute service? I ask because I would like to know if this feature would be available for just using the domain hosting.
Around April/May, they ran this course for free for 60 days. I progressed to few lessons, but had to stop as I had to focus on some critical stuff at work. I can tell it was good as far I went. I wish I convince my company next year to put us through this course.