Not to tread on Rob's toes.
It isn't strictly necessary, no. Though after seeing more of Robs method, it is a good idea. You can test each part or section to make sure it unfolds correctly. Then move onto another area. Saves doing it all just to find you have to redo some parts.
Good thinking Rob.
I'm with Lex on the colour too. Though I'll probably try to print mine to gold card. But that gold texture on the pic above looks real hot!