I communicate a lot with maybe a dozen Czech friends who are escorts working Zurich right now and I have never heard of any being asked for ID. Since EU rules also allow Brits to work, I don't know why you would stand out. Especially with all the Brazilians working Zurich now. Zurich is a good market, Europe's richest. Patagonya is good business-wise sometimes. Rentman is catching on slowly in Europe but Hunqz is still by far the biggest. Possibly 90% of the European market.
I'll be flying into Zurich to meet a couple Czech escort friends on the morning of the 29th of October. Then to Prague for a week and back to Zurich for two more days. I've finally decided it's easier to hit both towns than miss half the Czech guys who at any time are in Zurich. Be aware that rates are lower in Europe. Zurich has dropped to 150 while Prague has gone to 200 (it's the Hollywood of gay porn). There are few clients in Prague though and many rich ones in Zurich. I've heard of exceptional "appreciations" from Swiss clients and lavish trips. Germany is very active but has super low rates of 100.