I am testing a change based on Add a custom HTTP header to requests made to your Discourse [1] to add this header, I’ll let you know once I have verification it works.
Personally, I’m a fan of the suggestion someone made to outright reject requests that have the FLOC header sent, breaking Chrome. But I can’t find the article I read advocating that… 
GNU Terry Pratchett, speak his name ↩︎