[hagbard_c]

It might be possible to disable this feature through a policy file [1] just like other features can be disabled, e.g. here's how to disable auto-update:

   {
   "policies": 
      {
        "DisableAppUpdate": true
       }
   }

Create a text file named policies.json in a directory named distribution inside the Firefox installation directory. In my case that ends up looking like this:

   /opt/APPfirefox (package root)
   /opt/APPfirefox/firefox (currrent nightly)
   /opt/APPfirefox/bin/firefox-127.0a1 -> /opt/APPfirefox/firefox/firefox-127.0a1
   /opt/APPfirefox/distribution/policies.json

The browser sees this file and abides by its contents. Open about:policies#documentation in Firefox to see which policies can be configured this way.

[1] https://support.mozilla.org/en-US/kb/customizing-firefox-usi...