I actually have an theory for this one! Mind you most of this info is from my time doing medieval historical reenactment. So this is actually a very popular style for ring belts and other medieval style belts for reenactments based on the information we have on period fashion. They used this as a way to manage extra length and to get the length out of the way. Since you know- you didn't have pants loops back in the day. Sometimes the knot itself was even the way to fasten the belt. Point being, that it likely could be a small detail that shows the antiquated nature of Briar Valley, which is something I find very cool.