Ok great news, I just spoke with Romain and he clarified a few things.
Will get the box removed and checked here and see what the issue is, but it doesn't sound like anything too dramatic. The part will either be sent to me or worst case I can send the box back, but I really don't think that's required.

Just to clarify, it's a brilliant box otherwise and extremely smooth (And I've experienced a brand new MT75 box from ford before). The issue appears to be not related to the actual gearkit, it's with another part of the box so I still have confidence in the quality.