I'm Korean. I had V-line surgery 2 years ago at age 27. I'm 50/50 whether I regret it or not. The consultant was confused why I wanted V-line because "You already have a V-line". The biggest insecurity I wanted to address was my chin. It's a little big for my thin face (similar to Alodia Gosiengfiao/Xiaxue). My maxillary angle was actually close to perfect but I had my entire jaw bone cut off. I think I should've gotten mini V-line instead.
Before: Had a very defined jaw line that some people might be jealous of. V-shaped but kind of big chin.
After: Not very defined jaw. Looks fine if I face forward but if I scrunch my chin it looks like 5 chins. No sagging because my skin is 10 years younger than my age. I look younger than I did before.
My advice: Many people complain about having an Asian broad, flat face. Sometimes, the problem is not the shape of the mandible. It's because many Asians have a depressed mid-face and a protruding jaw (like black people but less obvious). The ideal "doll-face" that most people want is a prominent but short mid-face and a smaller jaw that goes back at an angle, instead of in-line with the nose. That was definitely my case. What I should've done instead is double-jaw surgery and fat-grafting to my mid-face. I have seen girls get double-jaw and it is WAY more effective than V-line alone. But, my natural face isn't really that bad and doesn't warrant double-jaw, one of the most invasive surgeries, so I probably wouldn't have done it.
Aging: Looking back at my old pictures, I looked better then, before all the plastic surgery, than I do now. I don't have the best bone structure and my skull is very asymmetrical. When I was younger all these things were barely noticeable because the fat on my face hid them. As my fat disappeared I started noticing things like depressed mid-face, uneven jaw, sunken eye socket, veiny temples, etc. My reaction to aging was getting big surgeries to make big changes, rather than address the main issue: age. If I could reverse all my surgeries I would start with anti-aging surgeries like fat-grafting, and see if I still want big changes. Facial contouring surgery won't make you look more beautiful unless you have a "deformity" to begin with, like overly large cheekbones or mandible. It will make you look different, but not necessarily better.