Distribution Block on Outside Wall

I'm replacing our plumbing with PEX and I'm about to install a Manabloc Distribution block. I wanted to see if anyone had any reasons why I shouldn't put it on an outside wall of my basement?

I live in St. Louis so the winters aren't like living in the Yukon, but it's not Florida either. The basement is heated/cooled and the foundation is 75% below grade.

Thanks,

-peel

PEX might be less likely to freeze than other materials, and more tolerant if it does, but the fittings sure aren't. Why take the chance if you can relocate the manifold/piping elsewhere.