I expect, but dont know, if the area behind the cladding will need to be ventilated, but i expect it will. So you will need to find something that leaves the gap free, usually 25mm, but expands to fill that gap in the event of a fire.
Also, my own thoughts are that any cladding on the outside, should be ventilated, at the top, and the bottom, together with gaps in any battens that allow airflow into areas, such as under windows etc.
Think of it as a roof that needs full ventilation. You could achieve full ventilation by using a cross batten system. Don't forget to mesh the top, and bottom to prevent, wasps, bees, mice etc, making a nice home behind your cladding. As for fire stops, in my opinion, don't be tempted to fully block the cavity, with fire socks, or you wont have any ventilation. I was pondering the same problem on a house that i didnt build in the end. Sorry, i could not find any products that would leave enough of the ventilation gap, and expand enough to close it, in the event of a fire.