Thanks a lot especially to @paulakreuzer, you gave me convincing arguments in favour of the slim cover and I think that’s what I will choose. Although I’m still a bit worried that it might introduce a new issue: There are reports about the slim case causing reboot loops due to the power button getting stuck in the pressed state, even causing overheating. See the thread “Slim Case - Reboots and Button-Issues” for example. But apparently swapping the on/off and camera buttons should help then.