I don't think I'll be going this again. Or I won't be advertising that we can do it anyways. It is hard as can be to do. and it's mostly guess work. If I were to do a helmet again, I certainly hope that it is one with more ridges and dips. Then I can template it, and install it in parts. Doing it all as one print is no easy stretch. Pun intended.
Update: The customer has been so happy with this design that they have ordered it 2 more times since. I adjusted the design slightly to improve the install, but otherwise it looks the same. The biggest benefits to the more recent installs have been innovation in the materials available, and a second set of hands to hold the helmet in place while installing.