Assign Secondary Attribute Manually in a Dashboard

Many of the dashboard tiles have secondary attributes that are automatically selected, battery level or temperature.


But this is not user configurable. Having a drop-down of all of the device's attributes would be very useful. We could then pick which attribute to put there. Maybe we want battery for some that display temp. Maybe we want temp for some that display battery. Or maybe we want to use a different attribute entirely. Adding that as user configurable would be a huge help. Thanks!!!