I don't really see a problem with the disconnect being on the roof.
Reason I say that, is because if there was a fire that required the disconnection of the panels, most fire appliances that I am aware of, carry a pike pole, these are inherently made from fibre-glass,with a steel tip, all that would be required, is an actuator (on the disconnect) in the shape of a ring to put the hook of the pike pole though and give the actuator a quick pull.
Having said that, I'm not entirely sure that down is off (isolated) over in the US, with a disconnect?
It wouldn't take much to isolate a solar installation at all, if that were the case.
Just my $0.02 worth.
