More accurately, Nostr + good anonymity opsec solves this. If you're in the UK and want to use Nostr for free speech, you need to utilize tools like Tor and use a random name generator (also carried out within Tor) to keep yourself safe. Some clients like Amethyst include the ability to enable Tor for all connections. However, the best (safest) solution would be to have a dedicated PC or laptop for this purpose. Install a Linux distribution of your choice, set up some sort of virtualization software (VirtualBox tends to be the most user-friendly, in my experience) and set up a Whonix installation. Once that's set up and updated, use that to access a Nostr web client of your choice (Primal includes a proxying feature, which could be an added layer of defense) and only post on Nostr from that virtual machine on that dedicated Linux system. Granted, that's a hardcore solution but with the direction the UK is going, it may become the only option for free speech for them.