As long as 4chan sells 4chan passes to UK citizens, they do business in the UK. They sell using crypto so there's not much for the UK to go after, but they do more than just "be available".

Two counter points. First, crypto is not part of the UK government's financial systems or institutions. They don't automatically hold jurisdiction over all crypto transactions, or more specifically, crypto service providers.

Second, again, 4chan does not operate in the UK. If someone in the UK purchases a 4chan pass, they have electronically transmitted their "money" over to the US to buy it. I would compare this to a UK citizen flying over to the US and buying a ticket, and bringing it back with them to the UK.

It's very clear, 4chan did not perform any business or transactions within UK jurisdiction.

Great! If this is so, then you should be able to prove that UK citizens are using crypto to purchase their services and that 4chan is expressly aware of this fact. I'm sure this proof will be forthcoming presently...