I think as long as the socks are the same pattern and general colors it's kind of OCD to expect more than that. Customs socks is going too far.
Considering this will be their 4th attempt at making this figure, they have no excuse not to get the right sock pattern and colors. The first release was forgivable since it was pre-release. The DX had no excuse IMO. And this even more so. If HT can't get this widely known detail right by now, they don't deserve to be in this business. It might be a minor detail to some, but they've put tiny details of less notice into their figures than this. Getting the big details right means nothing if you don't get the little ones right. Its the little details that make an average figure become amazing.