My point was that the talk about pin 2 vs pin 3 in terms of signal polarity is irrelevant when it comes to balanced cables. Since they are wired 2 to 2 and 3 to 3, they will work with either pin 2 "hot" or pin 3 "hot", and there are no special cables needed for one convention vs. the other. Have I missed something there?
This is correct. But some balanced gear inverts polarity, and some pro gear I’ve seen has a polarity switch at the XLR input. Point is, occasionally a custom XLR is needed.