You would get a nice improvement with lip fillers. These fillers, (Volbella, Restylane, Juvederm) are good to create a symmetrical lip. Nova threads can be used to improve lift and shape. Implants or fat are alternatives. Technique will be important here, so you'll want to see someone meticulous...
Thank you for sharing your excellent question. I think you should safely be able to have lip fillers placed without spread of your vitiligo. Hope this helps.
Typically a combination of treatments will yield the best result. Fillers, such as Volbella, which are thinner are recommended for the lip area. Other treatments such as lasers, chemical peels, and microneedling can help improve skin tone and texture.