I have looked into this issue. Love2D studio does not do anything special to setMode. But it seems to me, the screen resolution is determined by the iOS, and you cannot dynamically change it using love.window.setMode.
setMode still works, but not in the way as the the desktop. For example, we can
- love.window.setMode(2,1) change to landscape mode
- love.window.setMode(1,2) change to portrait mode
Hope it helps.