The workaround suggested by
BirdmanBerry in this thread:
https://www.pprune.org/computer-inte...l#post10863613 , to install the Privacy Badger extension, seems to work with Firefox as well as Chrome/Chromium.
It doesn't fix the fundamental flaw within the Trustarc script, as it just blocks the ability of PPRuNe to demonstrate compliance with the GDPR, so arguably it stops the forum from doing what it has to do, by law, within the EU. It is an easier workaround than either having to use a different device to browse PPRuNe or do something a bit out of the ordinary, like spoof your location using a VPN service.