Hello!
Swiss layouts have the umlauts, accordingly yes! See e.g.
https://youtu.be/wfCZP36Zgf... (Logitech Keys-To-Go - iPhone & iPad - HD Gameplay Trailer)
This does not correspond to the Android and Windows variant, but the layout should not differ technically. The German layout might be visible in the video, so it might look slightly different on the Swiss keyboard, but the umlauts are still there.
Greetings Domi
