Best option to soften lines not improved by neck lift?

Deep lines like your can not be corrected with neck/face lift. Between many techniques we have tried in the past our current treatment consists of injection of nano-fat grafts with a fine needle. That creates improvement we have not seen with other techniques. Hope this helps.

"Injecting soft fillers like Belotero in this area can reduce lines, wrinkles and folds as well as improve skin texture with long-term collagen production. Fillers are being used more frequently to contour and lift rather than solely line fill. Of course, fillers are best used in combination with lasers and microneedling​ with PRP to get the optimal outcome.

I suggest getting a formal evaluation with a cosmetic dermatologist to create an individualized treatment plan that works for you. Best, Dr. Emer"

Thank you for your question regarding the best option to soften lines on your neck. By examining your photos, it looks like the best option would be Morpheus8. Or if he has, it is new micro-needling technology that uses heat and radio frequency to help contract the skin. You would likely need at least three sessions to see a difference. I hope this helps answer your question regarding how to soften the lines on your neck.

Sincerely, Dr. Katzen. (“Verified” Plastic Surgeon, President of the American Society of Bariatric Plastic Surgeons, certified by the American Board of Plastic Surgery, Fellow of the International Society of Aesthetic Plastic Surgery, American College of Surgery, and International College of Surgery, and member of the American Society of Plastic Surgery, American Academy of Cosmetic Surgery and RealSelf Hall of Fame.)

I routinely tell all my lift patients that horizontal lines are not eliminated by face/neck lift surgery. Pull vectors in the neck would need to be vertical, which can be done on the face but not on the mid to lower neck. If you have already tried fillers, fat will not help. The horizontal lines are created by dermal retractions, which is why surface treatments like laser will not work, and fillers cannot balloon out tissue lines that are adherent to deeper tissue. The primary way to break up these lines is by open surgical elevation, with the hope that they don't reform. Lipocannula dissection will not break these lines up. However, the open surgical elevation of the skin carries a risk of bleeding and a risk that the lines may recur, which is why most surgeons would not embark on this path.

These lines are difficult to remove as you have witnessed.
I am using a new treatment of ultra-micro fat injections combined with growth factors
Early results are looking promising