I would guess that currency strength is not just tied to the economy in general, but also the banking system specifically. London has been a major banking center, and is likely to lose a lot of that.

It is not likely. It is a forgone conclusion if Brexit happens. From friends who are bankers in Europe. Currency traders apparently are betting that a hard Brexit will happen - due to incompetent leadership that British voters keep voting for. So dumb as to not constantly mock Boris Johnson. I cannot remember when the British pound had less value.

Plenty other industries also will suffer. Suddenly remaining UK industries must pay for tariffs - that also create recessions and eventually unemployment. British voters also want that - according to currency traders. When was a British pound worth less?

Well, the British will vote for a new Prime Minister. But only something like 130,000 of 67 million Brits will select one. What a screwed up nation. But that would not affect currency markets.