While it's true that there is no reason why you cannot, in theory, wear a metal cantled sporran for day wear, I can see the reason for Shaun's concern. Most readily available skunk fur sporrans with a metal cantle will look something like this one:

In my opinion, a bit much for day wear, though it might look just splendid with a formal doublet.

On the other hand, a similar sporran without the metal bits could be more versatile. Consider this skunk fur Glengyle from the Ferguson Britt line.


Here I am wearing one for a black tie Burns Dinner.


And here is McMurdo wearing the same style sporran in a more casual daywear setting.