When the club was invited to the Caterham Technology Centre, not long after the 160 was launched, they showed the how they had changed the values in the dampers for that model. They had a damper there where they showed the process. They also explained only mono tube dampers would work on a 7 due to the weight. Doesn't mean they haven't changed since.
My detailed build blog
Twin tubes are also problematic at angles of 45 degrees or more from vertical, so the inclination of the front dampers would put them close to that on a wide-track front suspension. Conceivably the rear dampers could be twin tube and the fronts mono tube.
It is actually important to find out if there is a floating piston in the Bilstein. I have never cut one open to find out.
If they are emulsion dampers which is entirely possible then they should have the body at the top so that the piston can sit in the oil until it becomes the emulsion.