Injectables can be a temporary solution for disguising bridge deformities but on the tip it's not easy. For post primary deformities it might help camouflage bridge bumps and irregularities.
This is what Dr. Rivkin says about injectables for his non surgical rhinoplasty-
believes modern medical technology can provide today’s patients with superior alternatives to invasive, painful surgery that requires a long recovery time.
This doesn't hold up because most primary rhinoplasty is about subtracting and not adding. His approach works for building up bridges but that's about it. For most it will not be a superior alternative to surgery.