I used to run Firefox with resist fingerprinting enabled. I believe it was causing chat time stamps on websites like WhatsApp to be incorrect, which was annoying but I don’t know if you consider that broken.
This is a great example of why I'm generally skeptical of these scattershot approaches to making users more secure by changing default settings in mainstream browsers. Security and privacy features always entail tradeoffs and should be designed and implemented holistically for best results.
This is why I, a privacy-conscious individual, don't follow any of these guides in my Firefox. If you follow the discussion on Bugzilla, the weekly team meeting notes, and occasionally ask respectful questions on Mozilla IRC, you come to a similar conclusion to me in that the Firefox development community is doing the right thing in not enabling this by default.