Great question!!!
Please understand that my post is best on personal experiences only:
The Cincture, of course, represents chastity.
At my parish, we have diocesan priests, and I have noticed different styles of cinctures among our priests and seminarians when they wear albs, some of which which tie differently. I always assumed it had to do with the style of the cincture.
Our altar servers used to wear cinctures with their albs and sometimes you had a smaller server who Would grab a much longer cincture than they needed and I would have to wrap it around their waist 2 or 3 times so they wouldn’t trip over the knots.