Just that. The switch cover should be there while the chamber is active and not when it's inactive - to prevent the destruction of a sample. This could work with other machines but the chamber needs it the most.
Switch covers are usually used to prevent accidental activation of a machine but I can't imagine how that would be useful. It's not like we can accidentally bump into a switch. The only thing that changes is requiring a double-click. On the other hand, I've managed to destroy a sample on accident when I tried to activate a second research chamber without closing the first p