This is an @atmasphere , question.
He was one of the first designers to offer equipment that used the AES 48 standard.
Long story short, designing equipment that not only offers XLR, but adheres to the AES standard, makes it challenging. Many offer XLR connectivity, but do not use the AES standard-which makes the XLR connection subject to cable influence.
Okay, I should probably back up even further.
The AES 48 standard insulates the cable from introducing 'cable artifacts'-or for a better phrase, 'cable sound'. This standard has been utilized by recording studios for decades. And, understandably so, considering that equipment is spaced over quite long distances.
So, when a manufacturer offers XLR/balanced, the equipment should adhere to the AES standard in order for the cable to introduce the minimal amount of 'coloration'.
Unfortunately, doing so makes it a bit of a design problem, albeit with additional cost.
Hopefully, Ralph(Atmasphere) will chime in.
Bob