Here’s a quick pic of my Shat with the black hose applied to the foam head. Turned out pretty nice 
That’s a great idea. I never thought about that.
If you have one, best way to avoid anything from happening is to wrap the head in a few plastic bags so that way none of the foam shows threw. After that to give it a clean look put black nylon over it. It helps give extra protected and blacks out the eyes of the mask on it. I have masks on like this for a few years with no problems.
I’m new to the mask community, and most are the cheaper version I repaint myself at the moment, doing it more for the craft aspect of it, but I have all mine so far in Styrofoam heads , but like above I put one or 2 black beanies on then to keep it away and black out the eyes and gives the masks a nice shape. Dollar tree sells black beanies for a buck I just go in and raid the place, I now have over 30 black beanies for upcoming masks. Can’t be too careful.