drilling roof for solar ...

My camper is in winter storage so I can't look at the roof and I have a question on running the wires down to the charge controller.

Our fridge vents through the side wall so I don't have a roof vent to use. Obviously I have holding tank vents but I don't know where they are in relation to where the panels will be vs where the charge controller will be.

My question is ... it seems that everyone is afraid of drilling through the roof to run the wires from the combiner box to the charge controller. I understand water leaks are a campers enemy, but with the sealing tech out there, if done correctly, is this really an issue?

Am I missing something?