Does roaming also work with the eSIM? 

Since the eSIM works just like a conventional SIM card, roaming via eSIM is of course also possible. However, there are certain devices that suppress roaming by default for reasons of cost protection. The Apple Watch is one of those devices.  

 

There are also specific eSIM providers for roaming tariffs in expensive zones. Airalo or Truphone are examples of such providers. For short stays or holidays in roaming zone 1 (EU/UK/USA), however, no separate provider is required due to the relatively cheap Swiss roaming packages. With the 10 GB package from Digital Republic, for example, you can surf the entire Zone 1 for just CHF 5 per gigabyte.