Unless this stuff uses methods unknown to me for gaining lots of mass really quickly, won't it be ridiculously light? Maybe as heavy as Styrofoam? Unless it's anchored solidly a little gust of wind could blow it away. I'm also wondering if they have a few different kinds of foam like this. I would imagine that they could design a similar foam that becomes like a marshmallow instead of hardening. That would have a few cool uses such as breaking a fall, or making a beanbag chair for your makeshift encampment.
It would also be cool to reprogram an MTC Gun Pit to project different shapes, such as a raft. Even more fun, equip your P4 drone with a specialized cutting tool and a healthy dose of this stuff, that is if your rigger has that sense of humor.