Hi Watts, although they control lights, wipers and climate temperature the sensor is one unit in front of the rear view mirror. Any of the 3 functions that misbehave, results in changing the whole unit.
( I did this on a previous Golf).
For the lights, the default setting for a broken sensor is for the lights to be on full time when the switch is set to auto. A working light sensor effectively turns the lights off in daylight.
Also coming home/ leaving functions don't work if sesnor has problems, check that?
When I had the issue on a previous Golf, it did occasionally inform me on the dash of issues with the light sensor, until you get that, hopefully there is nothing to worry about.
One thing to consider, if it does turn out to be a problem when they repaired your roof, did this involve removing the windscreen, or more likely the rear view mirror in the process?