CF-Priority has no effect on pushed scripts priority

I’ve read the article on HTTP/2 priority a dozen times, but I cannot seem to get the CF-Priority header to have any impact on the priority pushed scripts.

What I’m trying to do

  • Using webworkers + professional plan
  • Push 3 critical scripts
  • Push 5 more less critical scripts
  • Send CF-Priority headers to prioritize the requests.

I am sending the header

      response.headers.set('cf-priority', priority);

Where priority is "60/0" or "30/1" based on the pathname of the script.

The problem is that in Chrome it always shows High priority under the network tab. I’ve also recorded the network log and all the files are sent with the same priority.

Is this not possible or am I doing something wrong.

Note I am also sending an additional test header x-cf-priority with the same value, so I know my code that sets the header in the web worker is in the right place and actually working.