Hello,
   I live in climate zone 6a (coastal Maine). I have the opportunity to buy some discounted Thermax insulation for insulating my crawlspace. My only hesitation is that it’s specifically designed for metal buildings (Thermax metal building board). The only difference between the Thermax metal building board and more commonly used products for basements (Thermax sheathing and white finish) is in the details of the facers. The metal building board seems to have thicker foil facers (1.25 mil) on both sides to minimize moisture condensation. 

I want to install the insulation on my crawlspace walls, which are poured concrete. Would using metal building board for this application be:

a) no big deal
b) something I could horribly regret later

Thanks for your help!