Would I benefit more from Cool Sculpting, Kybella, or filler injections to thin out my jawline and double chin? (Photos)

Based on your photos, I believe chin liposuction would provide the best results for you. I do not think Kybella or CoolMini would be able to remove enough fat to produce satisfactory results. Chin liposuction is performed with local anesthesia and recovery is typically just a few days. Tiny incisions are used to insert micro-cannulas directly into the fat pocket and gentle suction eliminates it from the body. The procedure offers dramatic, long-lasting results when it is performed by a board-certified dermatologist with extensive training and experience in the process. 

my younger patients with neck sagging (and most of what you have Is sagging and not fat) do facetite + liposuction, threads, morpheus treatments every 2-4 months, and yearly thermage/ultherapy.  however it appears you may need an early neck lift to get the result you are looking for.With significant neck sagging you would need a neck/face lift with muscle tightening (platysmaplasty). at the same time lasers (fraxel,  co2 or erbium( or microneedling RF (fractora, intensif) can be . performed to improve the crepe skin or wrinkles.  You need a formal consultation, as the neck can be treated with a combination approach:
1. micro needling and lasers for texture
2. botox, disport or xeomin to help platysmal bands
3. intensif or fractora RF microneedling for crepe skin and lifting
4. fillers like belotero, restylane silk, juvederm volbella to improve lines and folds
5. neck/face lifting if sagging is prominent or early starting +/- platysmaplasty (muscle tightening)
6. J plasma/Renuvion, thermiRF, inmode facetite for internal tightening
7. ultherapy and thermage for external tightening
8. regular Venus legacy, exilis ultra, or inmode forma treatments with facials to maintain tightness
9. PDO novathreads or silhouette instalift cone threads for lifting and long-term collagen production
see an expert for a full evaluation and treatment plan based on your individual situation and goals.
Best, Dr. Emer.

Whenyou have this much fat in your double chin, I would never recommend that you use Kybella or coolsculpting. A single treatment of liposuction will result in instant outcome that you should be happy with. At the same time CoolSculpting or Kybella will need to be repeated multiple times and you will have to wait for over a year for the final result as well as will probably spend more money on such treatments. I hope this helps and good luck from New York City plastic surgery